Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises

Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises

These Solutions are part of Selina Concise Mathematics Class 10 ICSE Solutions. Here we have given Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises.

Sales-Tax (VAT)

Question 1.
A man purchased a pair of shoes for ₹809.60 which includes 8% rebate on the marked price and then 10% sales tax on the remaining price. Find the marked price of the pair of shoes.
Solution:
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Question 2.
The catalogue price of an article is ₹36,000. The shopkeeper gives two successive discounts of 10% each. He further gives an off-season discount of 5 % on the balance. If sales-tax at the rate 10% is charged on the remaining amount, find :
(i) the sales tax charged
(ii) the selling price of the article including sales-tax.
Solution:
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Question 3.
A sells an article to B for ₹80,000 and charges sales-tax at 8%. B sells the same article to C for ₹1,12,000 and charges sales- tax at the rate of 12%. Find the VAT paid by B in this transaction.
Solution:
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Question 4.
The marked price of an article is ₹1,600. Mohan buys this article at 20% discount and sells it at its marked price. If the sales-tax at each stage is 6%; find :
(i) the price at which the article can be bought,
(ii) the VAT (value added tax) paid by Mohan.
Solution:
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Question 5.
A sells an old laptop to B for ₹12,600; B sells it to C for ₹14,000 and C sells the same laptop to D for ₹16,000.
If the rate of VAT at each stage is 10%, find the VAT paid by :
(i) B
(ii) C
Solution:
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Banking

Question 6.
Ashok deposits ₹3200 per month in a cumulative account for 3 years at the rate of 9% per annum. Find the maturity value of this account
Solution:
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Question 7.
Mrs. Kama has a recurring deposit account in Punjab National Bank for 3 years at 8% p.a. If she gets ₹9,990 as interest at the time of maturity, find:
(i) the monthly instalment.
(ii) the maturity value of the account.
Solution:
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Question 8.
A man has a 5 year recurring deposit account in a bank and deposits ₹240 per month. If he receives ₹17,694 at the time of maturity, find the rate of interest.
Solution:
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Question 9.
Sheela has a recurring deposit account in a bank of ₹2,000 per month at the rate of 10% per anum. If she gets ₹83,100 at the time of maturity, find the total time (in years) for which the account was held.
Solution:
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Question 10.
A man deposits ₹900 per month in a recurring account for 2 years. If he gets 1,800 as interest at the time of maturity, find the rate of interest .
Solution:
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Shares And Dividend

Question 11.
What is the market value of 4 \(\frac { 1 }{ 2 }\) % (₹100) share, when an investment of ₹1,800 produces an income of ₹72 ?
Solution:
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Question 12.
By investing ₹10,000 in the shares of a company, a man gets an income of ₹800; the dividend being 10%. If the face-value of each share is ₹100, find :
(i) the market value of each share.
(ii) the rate per cent which the person earns on his investment.
Solution:
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Question 13.
A man holds 800 shares of ₹100 each of a company paying 7.5% dividend semiannually.
(i) Calculate his annual dividend.
(ii) If he had bought these shares at 40% premium, what percentage return does he get on his investment ?
Solution:
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Question 14.
A man invests ₹10,560 in a company, paying 9% dividend, at the time when its ₹100 shares can be bought at a premium of ₹32. Find:
(i) the number of shares bought by him;
(ii) his annual income from these shares and
(iii) the rate of return on his investment .
Solution:
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Question 15.
Find the market value of 12% ₹25 shares of a company which pays a dividend of ₹1,875 on an investment of ₹20,000.
Solution:
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Linear Inequations

Question 16.
The given diagram represents two sets A and B on real number lines.
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(i) Write down A and B in set builder notation.
(ii) Represent A ∪ B, A ∩ B, A’ ∩ B, A – B and B – A on separate number lines.
Solution:
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Question 17.
Find the value of x, which satisfy the inequation:
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Graph the solution set on the real number line .
Solution:
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Question 18.
State for each of the following statements whether it is true or false :
(a) If (x – a) (x – b) < 0, then x < a, and x < b.
(b) If a < 0 and b < 0, then (a + b)2 > 0.
(c) If a and b are any two integers such that a > b, then a2 > b2.
(d) If p = q + 2, then p > q.
(e) If a and b are two negative integers such that a < b , then \(\frac { 1 }{ a }\) < \(\frac { 1 }{ b }\)
Solution:
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Question 19.
Given 20 – 5x < 5(x + 8), find the smallest value of x when :
(i) x \(\epsilon\) I
(ii) x \(\epsilon\) W
(iii) x \(\epsilon\) N
Solution:
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Question 20.
If x \(\epsilon\) Z, solve : 2 + 4x < 2x – 5 < 3x. Also, represent its solution on the real number line.
Solution:
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Quadratic Equation

Question 21.
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Solution:
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Question 22.
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Solution:
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Question 23.
Find the value of k for which the roots of the following equation are real and equal k2x2 – 2 (2k -1) x + 4 = 0
Solution:
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Question 24.
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Solution:
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Question 25.
If -5 is a root of the quadratic equation 2x2 +px -15 = 0 and the quadratic equation p(x2 + x) + k = 0 has equal roots, find the value of k.
Solution:
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Problems On Quadratic Equations

Question 26.
x articles are bought at ₹(x – 8) each and (x – 2) some other articles are bought at ₹(x – 3) each. If the total cost of all these articles is ₹76, how many articles of first kind were bought ?
Solution:
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Question 27.
In a two digit number, the unit’s digit exceeds its ten’s digit by 2. The product of the given number and the sum of its digits is equal to 144. Find the number.
Solution:
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Question 28.
The time taken by a person to cover 150 km was 2.5 hours more than the time taken in return journey. If he returned at a speed of 10 km/hour more than the speed of going, what was the speed per hour in each direction ?
Solution:
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Question 29.
A takes 9 days more than B to do a certain piece of work. Together they can do the work in 6 days. How many days will A alone take to do the work ?
Solution:
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Question 30.
A man bought a certain number of chairs for ₹10,000. He kept one for his own use and sold the rest at the rate ₹50 more than he gave for one chair. Besides getting his own chair for nothing, he made a profit of ₹450. How many chairs did he buy ?
Solution:
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Question 31.
In the given figure; the area of unshaded portion is 75% of the area of the shaded portion. Find the value of x.
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Solution:
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Ratio And Proportion

Question 32.
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Solution:
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Question 33.
If a:b = 2:3,b:c = 4:5 and c: d = 6:7, find :a:b :c :d.
Solution:
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Question 34.
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Solution:
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Question 35.
Find the compound ratio of:
(i) (a-b) : (a+b) and (b2+ab): (a2-ab)
(ii) (x+y): (x-y); (x2+y2): (x+y)2 and (x2-y2)2: (x4-y4)
(iii) (x2– 25): (x2+ 3x – 10); (x2-4): (x2+ 3x+2) and (x + 1): (x2 + 2x)
Solution:
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Question 36.
The ratio of the prices of two fans was 16: 23. Two years later, when the price of the first fan had risen by 10% and that of the second by Rs. 477, the ratio of their prices became 11: 20. Find the original prices of two fans.
Solution:
The ratio of prices of two fans = 16 : 23
Let the price of first fan = 6x
then price of second fan = 23x
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Remainder And Factor Theorems

Question 37.
Given that x + 2 and x – 3 are the factors of x3 + ax + b, calculate the values of a and b. Also find the remaining factor.
Solution:
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Question 38.
Use the remainder theorem to factorise the expression 2x3 + 9x2 + 7x – 6 = 0 Hense, solve the equation 2x3 + 9x2 + 7 x – 6 = 0
Solution:
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Question 39.
When 2x3 + 5x2 – 2x + 8 is divided by (x – a) the remainder is 2a3 + 5a2. Find the value of a.
Solution:
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Question 40.
What number should be added to x3 – 9x2 – 2x + 3 so that the remainder may be 5 when divided by (x – 2) ?
Solution:
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Question 41.
Let R1 and R2 are remainders when the polynomials x3 + 2x2 – 5ax – 7 and x3 + ax2 – 12x + 6 are divided by (x +1) and (x – 2) respectively. If 2R1 + R2 = 6; find the value of a.
Solution:
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Matrices

Question 42.
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Solution:
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Question 43.
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Solution:
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Question 44.
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Solution:
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Question 45.
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Solution:
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Arithmetic Progression (A.P.)

Question 46.
Find the 15th term of the A.P. with second term 11 and common difference 9.
Solution:
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Question 47.
How many three digit numbers are divisible by 7 ?
Solution:
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Question 48.
Find the sum of terms of the A.P.: 4,9,14,…….,89.
Solution:
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Question 49.
Daya gets pocket money from his father every day. Out of the pocket money, he saves ₹2.75 on first day, ₹3.00 on second day, ₹3.25 on third day and so on. Find:
(i) the amount saved by Daya on 14th day.
(ii) the amount saved by Daya on 30th day.
(iii) the total amount saved by him in 30 days.
Solution:
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Question 50.
If the sum of first m terms of an A.P. is n and sum of first n terms of the same A.P. is m. Show that sum of first (m + n) terms of it is (m + n).
Solution:
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Geometric Progression (GP.)

Question 51.
3rd term of a GP. is 27 and its 6th term is 729; find the product of its first and 7th terms.
Solution:
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Question 52.
Find 5 geometric means between 1 and 27.
Solution:
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Question 53.
Find the sum of the sequence 96 – 48 + 24…. upto 10 terms.
Solution:
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Question 54.
Find the sum of first n terms of:
(i) 4 + 44 + 444 + …….
(ii) 0.7 + 0.77 + 0.777 + …..
Solution:
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Question 55.
Find the value of 0.4\(\mathring { 2 } \)\(\mathring { 3 } \).
Solution:
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Reflection

Question 56.
Find the values of m and n in each case if:
(i) (4, -3) on reflection in x-axis gives (-m, n)
(ii) (m, 5) on reflection in y-axis gives (-5, n-2)
(iii) (-6, n+2) on reflection in origin gives (m+3, -4)
Solution:
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Question 57.
Points A and B have the co-ordinates (-2,4) and (-4,1) respectively. Find :
(i) The co-ordinates of A’, the image of A in the line x = 0.
(ii) The co-ordinates of B’, the image of Bin y-axis.
(iii) The co-ordinates of A”, the image of A in the line BB’,
Hence, write the angle between, the lines A’A” and B B’. Assign a special name to the figure B’ A’ B A”
Solution:
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Question 58.
Triangle OA1B1 is the reflection of triangle OAB in origin, where A, (4, -5) is the image of A and B, (-7, 0) is the image of B.
(i) Write down the co-ordinates of A and B and draw a diagram to represent this information.
(ii) Give the special name to the quadrilateral ABA1 B1. Give reason.
(iii) Find the co-ordinates of A2, the image of A under reflection in x-axis followed by reflection in y-axis.
(iv) Find the co-ordinates of B2, the image of B under reflection in y-axis followed by reflection in origin.
(v) Does the quadrilateral obtained has any line symmetry ? Give reason.
(vi) Does it have any point symmetry ?
Solution:
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Section And Mid-Point Formulae

Question 59.
In what ratio does the point M (P, -1) divide the line segment joining the points A (1,-3) and B (6,2) ? Hence, find the value of p.
Solution:
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Question 60.
A (-4,4), B (x, -1) and C (6,y) are the vertices of ∆ABC. If the centroid of this triangle ABC is at the origin, find the values of x and y.
Solution:
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Question 61.
A (2,5), B (-1,2) and C (5,8) are the vertices of a triangle ABC. Pand Q are points on AB and AC respectively such that AP: PB=AQ: QC = 1:2.
(a) Find the co-ordinates of points P and Q
(b) Show that BC = 3 x PQ.
Solution:
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Question 62.
Show that the points (a, b), (a+3, b+4), (a -1, b + 7) and (a – 4, b + 3) are the vertices of a parallelogram.
Solution:
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Equation Of straight Line

Question 63.
Given points A(l, 5), B (-3,7) and C (15,9).
(i) Find the equation of a line passing through the mid-point of AC and the point B.
(ii) Find the equation of the line through C and parallel to AB.
(iii) The lines obtained in parts (i) and (ii) above, intersect each other at a point P. Find the co-ordinates of the point P.
(iv) Assign, giving reason, a special names of the figure PABC.
Solution:
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Question 64.
The line x- 4y=6 is the perpendicular bisector of the line segment AB. If B = (1,3); find the co-ordinates of point A.
Solution:
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Question 65.
Find the equation of a line passing through the points (7, -3) and (2, -2). If this line meets x- axis at point P and y-axis at point Q; find the co-ordinates of points P and Q.
Solution:
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Question 66.
A (-3,1), B (4,4) and C (1, -2) are the vertices of a triangle ABC. Find:
(i) the equation of median BD,
(ii) the equation of altitude AE.
Solution:
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Question 67.
Find the equation of perpendicular bisector of the line segment joining the points (4, -3) and (3,1).
Solution:
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Question 68.
(a) If (p +1) x + y = 3 and 3y – (p -1) x = 4 are perpendicular to each other find the value of p.
(b) If y + (2p +1) x + 3 = 0 and 8y – (2p -1) x = 5 are mutually prependicular, find the value of p.
Solution:
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Question 69.
The co-ordinates of the vertex A of a square ABCD are (1, 2) and the equation of the diagonal BD is x + 2y = 10. Find the equation of the other diagonal and the coordinates of the centre of the square.
Solution:
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Similarity

Question 70.
M is mid-point of a line segment AB; AXB and MYB are equilateral triangles on opposite sides of AB; XY cuts AB at Z. Prove that AZ = 2ZB.
Solution:
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Question 71.
In the given figure, if AC = 3cm and CB = 6 cm, find the length of CR.
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Solution:
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Question 72.
The given figure shows a trapezium in which AB is parallel to DC and diagonals AC and BD intersect at point O. If BO : OD = 4:7; find:
(i) ∆AOD : ∆AOB
(ii) ∆AOB : ∆ACB
(iii) ∆DOC : ∆AOB
(iv) ∆ABD : ∆BOC
Solution:
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Question 73.
A model of a ship is made to a scale of 1 : 160. Find :
(i) the length of the ship, if the length of its model is 1.2 m.
(ii) the area of the deck of the ship, if the area of the deck of its model is 1.2 m2.
(iii) the volume of the ship, if the volume of its model is 1.2m3.
Solution:
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Question 74.
In trapezium ABCD, AB || DC and DC = 2 AB. EF, drawn parallel to AB cuts AD in F and BC in E such that 4 BE = 3 EC. Diagonal DB intersects FE at point G Prove that: 7 EF = 10 AB.
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Solution:
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Loci

Question 75.
In triangle ABC, D is mid-point of AB and CD is perpendicular to AB. Bisector of ∠ABC meets CD at E and AC at F. Prove that:
(i) E is equidistant from A and B.
(ii) F is equidistant from AB and BC.
Solution:
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Question 76.
Use graph paper for this questions. Take 2 cm = 1 unit on both axes.
(i) Plot the points A (1,1), B (5,3) and C (2,7)
(ii) Construct the locus of points equidistant from A and B.
(iii) Construct the locus of points equidistant from AB and AC.
(iv) Locate the point P such that PA = PB and P is equidistant from AB and AC.
(v) Measure and record the length PA in cm.
Solution:
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Circles

Question 77.
In the given figure, ∠ADC = 130° and BC = BE. Find ∠CBE if AB ⊥ CE.
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Solution:
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Question 78.
In the given figure, ∠OAB=30° and ∠OCB= 57°, find ∠BOC and ∠AOC.
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Solution:
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Question 79.
In the given figure, O is the centre of the circle. If chord AB = chord AC, OP⊥ AB and OQ⊥ AC; show that: PB=QC.
Solution:
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Question 80.
In the given figure, AB and XY are diameters of a circle with centre O. If ∠APX=30°, find:
(i) ∠AOX
(ii) ∠APY
(iii) ∠BPY
(iv) ∠OAX
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Solution:
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Question 81.
(a) In the adjoining figure; AB = AD, BD = CD and ∠DBC = 2 ∠ABD.
Prove that: ABCD is a cyclic quadrilateral.
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(b) AB is a diameter of a circle with centre O, Chord CD is equal to radius OC. AC and BD produced intersect at P. Prove that ∠APB = 60°.
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Solution:
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Tangents And Intersecting Chords

Question 82.
In the given figure, AC=AB and ∠ABC=72°.
OA and OB are two tangents. Determine:
(i) ∠AOB
(ii) angle subtended by the chord AB at the centre.
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Solution:
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Question 83.
In the given figure, PQ, PR and ST are tangents to the same circle. If ∠P = 40° and ∠QRT = 75°, find a, b and c.
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Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 110.

Question 84.
In the given figure, ∠ABC = 90° and BC is diameter of the given circle. Show that:
(i) AC x AD =AB2
(ii) AC x CD = BC2
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Solution:
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Question 85.
In the given figure; AB, BC and CA are tangents to the given circle. If AB = 12 cm, BC = 8 cm and AC=10 cm, find the lengths of AD,BE = CF.
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Solution:
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Question 86.
(a) AB and CD are two chords of a circle intersecting at a point P inside the circle. If:
(i) AB = 24 cm, AP = 4 cm and PD = 8 cm, determine CP.
(ii) AP = 3 cm, PB = 2.5 cm and CD = 6.5 cm determine CP.
(b) AB and CD are two chords of a circle intersecting at a point P outside the circle. If:
(i) PA = 8 cm, PC – 5 cm and PD = 4 cm, determine AB.
(ii) PC = 30 cm, CD = 14 cm and PA = 24 cm, determine AB.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 115
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 116

Construction

Question 87.
Construct a triangle ABC in which AC = 5 cm, BC = 7 cm and AB = 6 cm.
(i) Mark D, the mid point of AB.
(ii) Construct a circle which touches BC at C and passes through D.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 117

Question 88.
Using ruler and compasses only, draw a circle of radius 4 cm. Produce AB, a diameter of this circle up to point X so that BX = 4cm. Construct a circle to touch AB at X and to touch the circle, drawn earlier externally.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 118

Mensuration

Question 89.
A cylindrical bucket 28 cm in diameter and 72 cm high is full of water. The water is emptied into a rectangular tank 66 cm long and 28 cm wide. Find the height of the water level in the tank.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 119

Question 90.
A tent is of the shape of right circular cylinder upto height of 3 metres and then becomes a right circular cone with a maximum height of 13.5 metres above the ground. Calculate the cost of painting the inner surface of the tent at Rs. 4 per sq. metre, if the radius of the base is 14 metres.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 120

Question P.Q.
In the given figure, diameter of the biggest semi-circle is 108cm, and diameter of the smallest circle is 36 cm. Calculate the area of the shaded portion.
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 121
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 122.

Question 91.
A copper wire of diameter 6 mm is evenly wrapped on the cylinder of length 18 cm and diameter 49 cm to cover the whole surface. Find:
(i) the length
(ii) the volume of the wire
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 123

Question 92.
A pool has a uniform circular cross-section of radius 5 m and uniform depth 1.4m. It is filled by a pipe which delivers water at the rate of 20 litres per sec. Calculate, in minutes, the time taken to All the pool. If the pool is emptied in 42 min. by another cylindrical pipe through which water flows at 2 m per sec, calculate the radius of the pipe in cm.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 124

Question 93.
A test tube consists of a hemisphere and a cylinder of the same radius. The volume of water required to fill the whole tube is 2849/3cm3 and 2618/3cm3 of water are required to fill the tube to a level which is 2 cm below the top of the tube. Find the radius of the tube and the length of its cylinderical part.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 125
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 126

Question 94.
A sphere is placed in an inverted hollow conical vessel of base radius 5 cm and vertical height 12 cm. If the highest point of the sphere is at the level of the base of the cone, find the radius of the sphere. Show that the volume of the sphere and the conical vessel are as 40 : 81.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 127
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 128

Question 95.
The difference between the outer and the inner curved surface areas of a hollow cylinder, 14cm. long is 88sq. cm. Find the outer and the inner radii of the cylinder given that the volume of metal used is 176 cu. cm.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 153

Trigonometry

Question 96.
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 130
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 131
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 132
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 133

Question 97.
If tan A = 1 and tan B = √3 ; evaluate :
(i) cos A cos B – sin A sin B
(ii) sin A cos B + cos A sin B
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 134

Question 98.
As observed from the top of a 100 m high light house, the angles, of depression of two ships approaching it are 30° and 45°. If one ship is directly behind the other, find the distance between the two ships.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 135

Question 99.
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 136
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 137

Question 100.
From the top of a light house, it is observed that a ship is sailing directly towards it and the angle of depression of the ship changes from 30° to 45° in 10 minutes. Assuming that the ship is sailing with uniform speed; calculate in how much more time (in minutes) will the ship reach to the light house.
Solution:
Let LM be the height of light house = h
Angle of depression changes from 30° to 45° in 10 minutes.
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 138

Statistics 

Question 101.
Calculate the mean mark in the distribution given below :
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 139
Also state (i) median class (ii) the modal class.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 140
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 141

Question 102.
Draw an ogive for the following distribution :
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 142
Use the ogive drawn to determine :
(i) the median income,
(ii) the number of employees whose income exceeds Rs. 190.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 143

Question 103.
The result of an examination are tabulated below :
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 144
Draw the ogive for above data and from it determine :
(i) the number of candidates who got marks less than 45.
(ii) the number of candidates who got marks more than 75.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 145

Probability

Question 104.
A bag contains a red ball, a blue ball and a yellow ball, all the balls being of the same size. If a ball is drawn from the bag, without looking into it, find the probability that the ball drawn is
(i) yellow
(ii) red
(iii) blue
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 146

Question 105.
A bag contains 6 red balls, 8 blue balls and 10 yellow balls, all the balls being of the same size. If a ball is drawn from the bag, without looking into it, find the probability that the ball drawn is
(i) yellow
(ii) red
(iii) blue
(iv) not yellow
(v) not blue
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 147

Question 106.
Two dice are thrown at the same time. Write down all the possible outcomes. Find the probability of getting the sum of two numbers appearing on the top of the dice as :
(i) 13
(ii) less than 13
(iii) 10
(iv) less then 10
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 148

Question 107.
Five cards : the ten, jack, queen, king and ace. of diamonds are well-shuffled with their face downwards. One card is then picked up at random.
(i) What is the probability that the card is the queen ?
(ii) If the queen is drawn and put aside, what is the probability that the second card picked up is (a) an ace ? (b) a queen ?
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 149

Question 108.
(i) A lot of 20 bulbs contains 4 defective bulbs, one bulb is drawn at random, from the lot. What is the probability that this bulb is defective ?
(ii) Suppose the bulb drawn in (i) is not defective and is not replaced. Now one bulb is drawn at random from the rest. What is the probability that this bulb is not defective?
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises image - 150

Hope given Selina Concise Mathematics Class 10 ICSE Solutions Chapterwise Revision Exercises  are helpful to complete your math homework.

ICSE Specimen Papers for Class 10 Home Science 2020, 2019, 2018

Download ICSE Specimen Papers 2020 Solved for Class 10 Home Science and Marking Scheme PDF. Here we have given ICSE Home Science Question Papers 2020 Solved. Students can view or download the Specimen Papers for ICSE 2020 with Answers Class 10 Home Science for their upcoming examination.

These ICSE Board Sample Papers are useful to understand the pattern of questions asked in the board exam. Know about the important concepts to be prepared for ICSE Class 10 Home Science board exam and Score More marks.

Board – Indian Certificate of Secondary Education (ICSE), www.cisce.org
Class – Class 10
Subject – Home Science
Year of Examination – 2020, 2019, 2018, 2017.

ICSE Class 10 Home Science Question Papers Solved

www.cisce.org ICSE Sample Papers for Class 10 Home Science are part of ICSE Specimen Papers Solved for Class 10 Here we have given ICSE Class 10 Home Science Sample Question Papers for Class 10 Home Science.

Year of ExaminationICSE Home Science Question Paper
2020Download PDF
2017Download PDF

The above ICSE Model Paper for Class 10 Home Science is the official sample paper released by ICSE Board as per latest syllabus of Class 10 Indian Certificate of Secondary Education, India.

We hope the ICSE Specimen Papers for Class 10 Home Science, help you. If you have any query regarding ICSE Class 10 Home Science Question Papers Solved, drop a comment below and we will get back to you at the earliest.

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers

Selina Publishers Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers

ICSE SolutionsSelina ICSE SolutionsML Aggarwal Solutions

APlusTopper.com provides step by step solutions for Selina Concise ICSE Solutions for Class 8 Mathematics Chapter 1 Rational Numbers. You can download the Selina Concise Mathematics ICSE Solutions for Class 8 with Free PDF download option. Selina Publishers Concise Mathematics for Class 8 ICSE Solutions all questions are solved and explained by expert mathematic teachers as per ICSE board guidelines.

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Rational Numbers Exercise 1A – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Add, each pair of rational numbers, given below, and show that their addition (sum) is also a rational number:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 1
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 2
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 3
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 4
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 5
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 6
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 7

Question 2.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 8
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 9
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 10
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 11
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 12
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 13
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 14

Question 3.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 15
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 16
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 17
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 18
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 20
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 22

Question 4.
For each pair of rational numbers, verify commutative property of addition of rational numbers:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 23
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 24
This verifies the commutative property for the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 25
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 26
This verifies the commutative property for the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 27
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 28
This verifies the commutative property for the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 29
This verifies the commutative property for the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 30
This verifies the commutative property for the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 31
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 32
This verifies the commutative property for the addition of rational numbers.

Question 5.
For each set of rational numbers, given below, verify the associative property of addition of rational numbers:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 33
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 34
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 35
This verifies associative property of the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 36
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 37
This verifies associative property of the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 38
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 39
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 40
This verifies associative property of the addition of rational numbers.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 41
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 42

Question 6.
Write the additive inverse (negative) of:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 43
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 44

Question 7.
Fill in the blanks:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 45
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 46
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 47

Question 8.
State, true or false:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 48
Solution:
(i) False
(ii) False
(iii) True
(iv) True
(v) False
(vi) False

Rational Numbers Exercise 1B – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 49
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 50
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 51
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 52
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 53

Question 2.
Subtract:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 54
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 55
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 56
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 57
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 58

Question 3.
The sum of two rational numbers is \(\frac { 9 }{ 20 }\). If one of them is \(\frac { 2 }{ 5 }\), find the other.
Solution:
The sum of two rational numbers = \(\frac { 9 }{ 20 }\)
And, one of the numbers = \(\frac { 2 }{ 5 }\)
The other rational number
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 59

Question 4.
The sum of the two rational numbers is \(\frac { -2 }{ 3 }\). If one of them is \(\frac { -8 }{ 5 }\), find the other.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 60
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 61

Question 5.
The sum of the two rational numbers is -6. If one of them is \(\frac { -8 }{ 5 }\), find the other.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 62

Question 6.
Which rational number should be added to \(\frac { -7 }{ 8 }\) to get \(\frac { 5 }{ 9 }\) ?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 63

Question 7.
Which rational number should be added to \(\frac { -5 }{ 9 }\) to get \(\frac { -2 }{ 3 }\) ?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 64

Question 8.
Which rational number should be subtracted from \(\frac { -5 }{ 6 }\) to get \(\frac { 4 }{ 9 }\) ?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 65

Question 9.
(i) What should be subtracted from -2 to get \(\frac { 3 }{ 8 }\)
(ii) What should be added to -2 to get \(\frac { 3 }{ 8 }\)
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 66
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 67

Question 10.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 68
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 69
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 70
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 71
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 72

Rational Numbers Exercise 1C – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 73
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 74
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 75

Question 2.
Multiply:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 76
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 77
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 78

Question 3.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 79
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 80
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 81
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 82
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 83

Question 4.
Multiply each rational number, given below, by one (1):
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 84
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 85
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 86

Question 5.
For each pair of rational numbers, given below, verify that the multiplication is commutative:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 87
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 88
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 89

Question 6.
Write the reciprocal (multiplicative inverse) of each rational number, given below :
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 90
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 91

Question 7.
Find the reciprocal (multiplicative inverse) of:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 92
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 93
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 94

Question 8.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 95
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 96
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 97

Question 9.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 98
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 99
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 100

Question 10.
Name the multiplication property of rational numbers shown below :
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 101
Solution:
(i) Commutativity property.
(ii) Associativity property.
(iii) Distributivity property.
(iv) Existence of inverse.
(v) Existence of identity.
(vi) Existence of inverse.

Question 11.
Fill in the blanks:
(i) The product of two positive rational numbers is always ……………
(ii) The product of two negative rational numbers is always ……………
(iii) If two rational numbers have opposite signs then their product is always …………..
(iv) The reciprocal of a positive rational number is ………. and the reciprocal of a negative raitonal number is ……………
(v) Rational number 0 has ………….. reciprocal.
(vi) The product of a rational number and its reciprocal is ………..
(vii) The numbers ……….. and ……….. are their own reciprocals.
(viii) If m is reciprocal of n, then the reciprocal of n is ………….
Solution:
(i) The product of two positive rational numbers is always positive.
(ii) The product of two negative rational numbers is always positive.
(iii) If two rational numbers have opposite signs then their product is always negative.
(iv) The reciprocal of a positive rational number is positive and the reciprocal of a negative raitonal number is negative.
(v) Rational number 0 has no reciprocal.
(vi) The product of a rational number and its reciprocal is 1.
(vii) The numbers 1 and -1 are their own reciprocals.
(viii)If m is reciprocal of n, then the reciprocal of n is m.

Rational Numbers Exercise 1D – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Evaluate:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 102
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 103
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 104
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 105
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 106
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 107

Question 2.
Divide:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 108
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 109
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 110

Question 3.
The product of two rational numbers is -2. If one of them is \(\frac { 4 }{ 7 }\), find the other.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 111

Question 4.
The product of two numbers is \(\frac { -4 }{ 9 }\). If one of them is \(\frac { -2 }{ 27 }\), find the other.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 112

Question 5.
m and n are two rational numbers such that
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 113
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 114

Question 6.
By what number must \(\frac { -3 }{ 4 }\) be multiplied so that the product is \(\frac { -9 }{ 16 }\) ?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 115

Question 7.
By what number should \(\frac { -8 }{ 13 }\) be multiplied to get 16?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 116

Question 8.
If 3\(\frac { 1 }{ 2 }\) litres of milk costs ₹49, find the cost of one litre of milk?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 117

Question 9.
Cost of 3\(\frac { 2 }{ 5 }\) metre of cloth is ₹88\(\frac { 1 }{ 2 }\). What is the cost of 1 metre of cloth?
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 118

Question 10.
Divide the sum of \(\frac { 3 }{ 7 }\) and \(\frac { -5 }{ 14 }\) by \(\frac { -1 }{ 2 }\).
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 119
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 120

Question 11.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 121
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 122
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 123
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 124

Question 12.
The product of two rational numbers is -5. If one of these numbers is \(\frac { -7 }{ 15 }\), find the other.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 125
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 126

Question 13.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 127
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 128
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 129

Rational Numbers Exercise 1E – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 130
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 131

Question 2.
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 132
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 133

Question 3.
Insert one rational number between (0 7 and 8 (ii) 3.5 and 5
(i) 2 and 3.2
(ii) 3.5 and 5
(iii) 2 and 3.2
(iv) 4.2 and 3.6
(v) \(\frac { 1 }{ 2 }\) and 2
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 134
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 135

Question 4.
Insert two rational numbers between
(i) 6 and 7
(ii) 4.8 and 6
(iii) 2.7 and 6.3
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 136
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 137
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 138

Question 5.
Insert three rational numbers between
(i) 3 and 4
(ii) 10 and 12
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 139

Question 6.
Insert five rational numbers between \(\frac { 3 }{ 5 }\) and \(\frac { 2 }{ 5 }\)
Solution:
LCM of denominators 5 and 3 is 15
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 140

Question 7.
Insert six rational numbers between \(\frac { 5 }{ 6 }\) and \(\frac { 8 }{ 9 }\)
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 141
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 142

Question 8.
Insert seven rational numbers between 2 and 3.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 1 Rational Numbers image - 143

Selina Concise Mathematics Class 10 ICSE Solutions Similarity

Selina Concise Mathematics Class 10 ICSE Solutions Similarity (With Applications to Maps and Models)

Selina Publishers Concise Mathematics Class 10 ICSE Solutions Chapter 15 Similarity (With Applications to Maps and Models)

Similarity Exercise 15A – Selina Concise Mathematics Class 10 ICSE Solutions

Question 1.
In the figure, given below, straight lines AB and CD intersect at P; and AC // BD. Prove that:
(i) ∆APC and ∆BPD are similar.
(ii) If BD = 2.4 cm AC = 3.6 cm, PD = 4.0 cm and PB = 3.2 cm; find the lengths of PA and PC.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 1
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 2
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 3

Question 2.
In a trapezium ABCD, side AB is parallel to side DC; and the diagonals AC and BD intersect each other at point P. Prove that:
(i) ∆APB is similar to ∆CPD
(ii) PA × PD = PB × PC
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 4
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 5

Question 3.
P is a point on side BC of a parallelogram ABCD. IfDPproduced meets AB produced at point L, prove that:
(i) DP: PL = DC: BL.
(ii) DL: DP=AL: DC.
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 6
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 7
Question 4.
In quadrilateral ABCD, the diagonals AC and BD intersect each other at point O. If AO = 2CO and BO=2DO; show that:
(i) ∆AOB is similar to ∆COD.
(ii) OA × OD – OB × OC.
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 8
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 9

Question 5.
In ∆ABC, angle ABC is equal to twice the angle ACB, and bisector of angle ABC meets the opposite side at point P. Show that:
(i) CB: BA=CP: PA
(ii) AB × BC = BP × CA
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 10
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 11

Question 6.
In ∆ABC; BM ⊥ AC and CN ⊥ AB; show that:
\(\frac{\mathbf{A B}}{A C}=\frac{B M}{C N}=\frac{A M}{A N}\)
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 12

Question 7.
In the given figure, DE//BC, AE = 15 cm, EC = 9 cm, NC = 6 cm and BN = 24 cm.
(i) Write all possible pairs of similar triangles.
(ii) Find lengths of ME and DM.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 13
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 14
(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 15

Question 8.
In the given figure, AD =AE and AD2 = BD × EC
Prove that: triangles ABD and CAE are similar.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 16
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 17

Question 9.
In the given figure, AB // DC, BO = 6 cm and DQ = 8 cm; find: BP × DO.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 18
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 19

Question 10.
Angle BAC of triangle ABC is obtuse and AB =AC. P is a point in BC such that PC = 12 cm. PQ and PR are perpendiculars to sides AB and AC respectively. If PQ = 15 cm and PR=9 cm; find the length of PB
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 20

Question 11.
State, true or false:
(i) Two similar polygons are necessarily congruent.
(ii) Two congruent polygons are necessarily similar.
(iii) All equiangular triangles are similar.
(iv) All isosceles triangles are similar.
(v) Two isosceles-right triangles are similar.
(vi) Two isosceles triangles are similar, if an angle of one is congruent to the corresponding angle of the other.
(vii) The diagonals of a trapezium, divide each other into proportional segments.
Solution:
(i) False
(ii) True
(iii) True
(iv) False
(v) True
(vi) True
(vii) True

Question 12.
Given = ∠GHE = ∠ DFE = 90°, DH = 8, DF = 12, DG = 3x + 1 and DE = 4x + 2.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 21
Find; the lengths of segments DG and DE.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 22

Question 13.
D is a point on the side BC of triangle ABC such that angle ADC is equal to angle BAC. Prove that CA2 = CB × CD.
Solution:

Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 23

Question 14.
In the given figure, ∆ABC and ∆AMP are right angled at B and M respectively. Given AC = 10 cm, AP = 15 cm and PM = 12 cm.
(i) Proe that ∆ABC ~ ∆AMP
(ii) Find AB and BC.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 24

Question 15.
Given : RS and PT are altitudes of A PQR prove that:
(i)∆PQT ~ ∆QRS,
(ii) PQ × QS = RQ × QT.
Solution:

Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 25

Question 16.
Given : ABCD is a rhombus, DPR and CBR are straight lines
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 26
Prove that: DP × CR = DC × PR.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 27

Question 17.
Given: FB = FD, AE ⊥ FD and FC ⊥ AD. Prove : \(\frac{\mathbf{F B}}{\mathbf{A D}}=\frac{\mathbf{B C}}{\mathbf{E} \mathbf{D}}\)
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 28

Question 18.
In ∆ PQR, ∠ Q = 90° and QM is perpendicu¬lar to PR, Prove that:
(i) PQ2 = PM × PR
(ii) QR2 = PR × MR
(iff) PQ2 + QR2 = PR2
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 29

Question 19.
In ∆ ABC, ∠ B = 90° and BD × AC.
(i) If CD = 10 cm and BD = 8 cm; find AD.
(ii) If AC = 18 cm and AD = 6 cm; find BD.
(iii) If AC = 9 cm, AB = 7 cm; find AD.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 30
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 31

Question 20.
In the figure, PQRS is a parallelogram with PQ = 16 cm and QR = 10 cm. L is a point on PR such that RL : LP = 2 : 3. QL produced meets RS at M and PS produced at N.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 32
Find the lengths of PN and RM.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 33

Question 21.
In quadrilateral ABCD, diagonals AC and BD intersect at point E. Such that
AE : EC = BE :’ED.
Show that ABCD is a parallelogram
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 34

Question 22.
In ∆ ABC, AD is perpendicular to side BC and AD2 = BD × DC.
Show that angle BAC = 90°
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 35
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 36

Question 23.
In the given figure AB // EF // DC; AB ~ 67.5 cm. DC = 40.5 cm and AE = 52.5 cm.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 37
(i) Name the three pairs of similar triangles.
(ii) Find the lengths of EC and EF.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 38

Question 24.
In the given figure, QR is parallel to AB and DR is parallel to QB.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 39
Prove that— PQ2 = PD × PA.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 40

Question 25.
Through the mid-point M of the side CD o£. a parallelogram ABCD, the line BM is drawn ‘ intersecting diagonal AC in L and AD produced in E.
Prove that : EL = 2 BL.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 41

Question 26.
In the figure given below P is a point on AB such that AP : PB = 4 : 3. PQ is parallel to AC.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 42
(i) Calculate the ratio PQ : AC, giving reason for your answer.
(ii) In triangle ARC, ∠ ARC = 90° and in triangle PQS, ∠ PSQ = 90°. Given QS = 6 cm, calculate the length of AR. [1999]
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 43

Question 27.
In the right angled triangle QPR, PM is an altitude.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 44
Given that QR = 8 cm and MQ = 3.5 cm. Calculate, the value of PR., [2000]
Given— In right angled ∆ QPR, ∠ P = 90° PM ⊥ QR, QR = 8 cm, MQ = 3.5 cm
Calculate— PR
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 45

Question 28.
In the figure given below, the medians BD and CE of a triangle ABC meet at G.
Prove that—
(i) ∆ EGD ~ ∆ CGB
(ii) BG = 2 GD from (i) above.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 46

Similarity Exercise 15B – Selina Concise Mathematics Class 10 ICSE Solutions

Question 1.
In the following figure, point D divides AB in the ratio 3:5. Find:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 46
Also, if:
(iv) DE = 2.4 cm, find the length of BC.
(v) BC = 4.8 cm, find the length of DE.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 48
Solution:
(i).
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 49

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 49

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 51

(iv)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 52

(v)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 52

Question 2.
In the given figure, PQ//AB;
CQ = 4.8 cm QB = 3.6 cm and AB = 6.3 cm. Find:
(i) \(\frac{\mathbf{C P}}{\mathbf{P A}}\)
(ii) PQ
(iii) If AP=x, then the value of AC in terms of x.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 54
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 55

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 56

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 56

Question 3.
A line PQ is drawn parallel tp the side BC of AABC which cuts side AB at P and side AC at Q. If AB = 9.0 cm, CA=6.0 cm and AQ = 4.2 cm, find the length of AP.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 58

Question 4.
In ∆ABC, D and E are the points on sides AB and AC respectively.
Find whether DE // BC, if:
(i) AB=9 cm, AD=4 cm, AE=6 cm and EC = 7.5 cm.
(ii) AB=63 cm, EC=11.0 cm, AD=0.8 cm and AE = 1.6 cm.
Solution
(i).
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 58

(ii).
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 60

Question 5.
In the given figure, ∆ABC ~ ∆ADE. If AE: EC = 4 :7 and DE = 6.6 cm, find BC. If ‘x’ be the length of the perpendicular fromA to DE, find the length of perpendicular from
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 61
A to DE find the length of perpendicular from A to BC in terms of ‘x’.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 62

Question 6.
A line segment DE is drawn parallel to base BC of AABC which cuts AB at point D and AC at point E. If AB = 5 BD and EC=3.2 cm, find the length of AE.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 63

Question 7.
In the figure, given below, AB, Cd and EFare parallel lines. Given AB = 7.5 cm, DC =y cm, EF=4.5 cm, BC=x cm and CE=3 cm, calculate the values of x and y.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 64
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 65

Question 8.
In the figure, given below, PQR is a right- angle triangle right angled at Q. XY is parallel to QR, PQ = 6 cm, P Y=4 cm and PX : XQ = 1:2. Calculate the lengths of PR and QR.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 66
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 66

Question 9.
In the following figure, M is mid-point of BC of a parallelogram ABCD. DM intersects the diagonal AC at P and AB produced at E. Prove that PE = 2PD.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 68
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 69

Question 10.
The given figure shows a parallelogram ABCD. E is a point in AD and CE produced meets BA produced at point F. IfAE=4 cm, AF = 8 cm and AB = 12 cm, find the perimeter of the parallelogram ABCD.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 70
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 71

Similarity Exercise 15C – Selina Concise Mathematics Class 10 ICSE Solutions

Question 1.
(i) The ratio between the corresponding sides of two similar triangles is 2 is to 5. Find the ratio between the areas of these triangles.
(ii) Areas of two similar triangles are 98 sq. cm and 128 sq. cm. Find the ratio between the lengths of their corresponding sides.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 72

Question 2.
A line PQ is drawn parallel to the base BC, of ∆ ABC which meets sides AB and AC at points P and Q respectively. If AP = \(\frac{1}{3}\) PB; find the value of:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 73
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 74

Question 3.
The perimeters of two similar triangles are 30 cm and 24cm. If one side of first triangle is 12cm, determine the corresponding side of the second triangle.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 75

Question 4.
In the given figure AX : XB = 3 : 5
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 75
Find :
(i) the length of BC, if length of XY is 18 cm.
(ii) ratio between the areas of trapezium XBCY and triangle ABC.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 77

Question 5.
ABC is a triangle. PQ is a line segment intersecting AB in P and AC in Q such that PQ || BC and divides triangle ABC into two parts equal in area. Find the value of ratio BP : AB.
Given— In ∆ ABC, PQ || BC in such away that area APQ = area PQCB
To Find— The ratio ol’ BP : AB
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 78
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 78

Question 6.
In the given triangle PQR, LM is parallel to QR and PM : MR = 3 : 4
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 80
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 81
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 82

Question 7.
The given diagram shows two isosceles triangles which are similar also. In (he given dia¬gram, PQ and BC are not parallel:
PC = 4, AQ = 3, QB = 12, BC = 15 and AP = PQ.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 83
Calculate—
(i) the length of AP
(ii) the ratio of the areas of triangle APQ and triangle ABC.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 84

Question 8.
In the figure, given below, ABCD is a parallelogram. P is a point on BC such that BP : PC =1:2. DP produced meets AB produced at Q. Given the area of triangle CPQ = 20 cm2.
Calculate—
(i) area of triangle CDP
(ii) area of parallelogram ABCD [1996]
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 85
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 86.

Question 9.
In the given figure. BC is parallel to DE. Area of triangle ABC = 25 cm2.
Area of trapezium BCED = 24 cm2 and DE = 14 cm. Calculate the length of BC.
Also. Find the area of triangle BCD.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 87
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 88

Question 10.
The given figure shows a trapezium in which AB is parallel to DC and diagonals AC and BD intersect at point P. If AP : CP = 3 : 5.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 89
Find:
(i) ∆ APB : ∆ CPB
(ii) ∆ DPC : ∆ APB
(iii) ∆ ADP : ∆ APB
(iv) ∆ APB : ∆ ADB
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 90

Question 11.
In the given figure, ARC is a triangle. DE is parallel to BC and \(\frac{A D}{D B}=\frac{3}{2}\).
(i) Determine the ratios \(\frac{A D}{A B}, \frac{D E}{B C}\).
(ii) Prove that ∆DEF is similar to ∆CBF. Hence, find \(\frac{E F}{F B}\).
(iii) What is the ratio of the areas of ∆DEF and ∆BFC?
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 91
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 92

Question 12.
In the given figure, ∠B = ∠E, ∠ACD = ∠BCE, AB=10.4 cm and DE=7.8 cm. Find the ratio between areas of the ∆ABC and ∆DEC.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 93
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 94

Question 13.
Triangle ABC is an isosceles triangle in which AB = AC = 13 cm and BC = 10 cm. AD is perpendicular to BC. If CE = 8 cm and EF ⊥ AB, find:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 95
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 96

Similarity Exercise 15D – Selina Concise Mathematics Class 10 ICSE Solutions

Question 1.
A triangle ABC has been enlarged by scale factor m = 2.5 to the triangle A’ B’ C’. Calculate:
(i) the length of AB, if A’ B’ = 6 cm.
(ii) the length of C’ A’ if CA = 4 cm.
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 1

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 2

Question 2.
A triangle LMN has been reduced by scale factor 0.8 to the triangle L’ M’ N’. Calculate:
(i) the length of M’ N’, if MN = 8 cm.
(ii) the length of LM, if L’ M’ = 5.4 cm.
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 3

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 4

Question 3.
A triangle ABC is enlarged, about the point O as centre of enlargement, and the scale factor is 3. Find:
(i) A’ B’, if AB = 4 cm.
(ii) BC, if B’ C’ = 15 cm.
(iii) OA, if OA’= 6 cm.
(iv) OC’, if OC = 21 cm.
Also, state the value of:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 97
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 5

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 6

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 7

(iv)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 16

Question 4.
A model of an aeroplane is made to a scale of 1:400. Calculate:
(i) the length, in cm, of the model; if the length of the aeroplane is 40 m.
(ii) the length, in m, of the aeroplane, if length of its model is 16 cm.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 8

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 9

Question 5.
The dimensions of the model of a multistorey building are 1.2 m × 75 cm × 2 m. If the scale factor is 1:30; find the actual dimensions of the building.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 10

Question 6.
On a map drawn to a scale of 1: 2,50,000; a triangular plot of land has the following measurements : AB = 3 cm, BC = 4 cm and angle ABC = 90°.
Calculate:
(i) the actual lengths of AB and BC in km.
(ii) the area of the plot in sq. km.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 11

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 12

Question 7.
A model of a ship of made to a scale 1 : 300
(i) The length of the model of ship is 2 m. Calculate the lengths of the ship.
(ii) The area of the deck ship is 180,000 m2. Calculate the area of the deck of the model.
(iii) The volume of the model in 6.5 m3. Calculate the volume of the ship. (2016)
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 97

Question 7(old).
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 17
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 99

Question 8.
An aeroplane is 30 in long and its model is 15 cm long. If the total outer surface area of the model is 150 cm2, find the cost of painting the outer surface of the aeroplane at the rate of ₹ 120 per sq. m. Given that 50 sq. m of the surface of the aeroplane is left for windows.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 100

Similarity Exercise 15E – Selina Concise Mathematics Class 10 ICSE Solutions

Question 1.
In the following figure, XY is parallel to BC, AX = 9 cm, XB = 4.5cm and BC = 18 cm.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 101
Find:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 102
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 154

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 155

Question 2.
In the following figure, ABCD to a trapezium with AB//DC. If AB = 9 cm, DC = 18 cm, CF= 13.5 cm, AP=6 cm and BE = 15 cm.
Calculate:
(i) EC
(ii) AF
(iii) PE
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 103
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 156

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 157

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 158

Question 3.
In the following figure, AB, CD and EF are perpendicular to the straight line BDF.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 104
If AB = x and CD = z unit and EF = y unit, prove that : \(\frac{1}{x}+\frac{1}{y}=\frac{1}{z}\).
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 160
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 161

Question 4.
Triangle ABC is similar to triangle PQR. If AD and PM are corresponding medians of the two triangles, prove that:
\(\frac{A B}{P Q}=\frac{A D}{P M}\).
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 163

Question 5.
Triangle ABC is similar to triangle PQR. If AD and PM are altitudes of the two triangles,
prove that: \(\frac{\mathrm{AB}}{\mathrm{PQ}}=\frac{\mathrm{AD}}{\mathrm{PM}}\)
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 164

Question 6.
Triangle ABC is similar to triangle PQR. If bisector of angle BAC meets BC at point D and bisector of angle QPR meets QR at point M, prove that: \(\frac{A B}{P Q}=\frac{A D}{P M}\).
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 162

Question 7.
In the following figure, ∠AXY = ∠AYX. If \(\frac{\mathbf{B X}}{\mathbf{A X}}=\frac{\mathbf{C} \mathbf{Y}}{\mathbf{A} \mathbf{Y}}\), show that triangle ABC is isosceles.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 105
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 13
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - `14
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 14
Question 8.
In the following diagram, lines l, m and n are parallel to each other. Two transversals p and q intersect the parallel lines at points A, B, C and P, Q, R as shown.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 106
Prove that: \(\frac{A B}{B C}=\frac{P Q}{Q R}\)
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 107

Question 9.
In the following figure, DE //AC and DC //AP. Prove that: \(\frac{B E}{E C}=\frac{B C}{C P}\)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 108
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 166

Question 10.
In the figure given below, AB//EF// CD. If AB = 22.5 cm, EP = 7.5 cm, PC = 15 cm and DC = 27 cm.
Calculate:
(i) EF
(ii) AC
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 109
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 167

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 168

Question 11.
In ∆ABC, ∠ABC = ∠DAC. AB = 8 cm, AC = 4 cm, AD = 5 cm.
(i) Prove that ∆ACD is similar to ∆BCA.
(ii) Find BC and CD.
(iii) Find area of ∆ACD: area of ∆ABC. (2014)
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 169

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 170

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 171

Question 12.
In the given triangle P, Q and R are the midpoints of sides AB, BC and AC respectively. Prove that triangle PQR is similar to triangle ABC.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 110
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 111

Question 13.
In the following figure, AD and CE are medians of ∆ ABC. DF is drawn parallel to CE. Prove that:
(i) EF = FB;
(ii) AG : GD = 2 : 1
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 112
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 113

Question 14.
The two similar triangles are equal in area. Prove that the triangles are congruent.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 114

Question 15.
The ratio between the altitudes of two similar triangles is 3 : 5; write the ratio between their:
(i) medians
(ii) perimeters
(iii) areas
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 115

Question 16.
The ratio between the areas of two similar triangles is 16 : 25. Find the ratio between their:
(i) perimeters
(ii) altitudes
(iii) medians.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 116

Question 17.
The following figure shows a triangle PQR in which XY is parallel to QR. If PX: XQ = 1:3 and QR = 9 cm, find the length of XY.
Further, if the area of ∆ PXY = x cm2; find in terms of x, the area of :
(i) triangle PQR.
(ii) trapezium XQRY.
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Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 118

Question 18.
On a map, drawn to a scale of 1 : 20000, a rectangular plot of land ABCD has AB = 24 cm, and BC = 32 cm. Calculate :
(i) The diagonal distance of the plot in kilometre
(ii) The area of the plot in sq. km.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 120

Question 19.
The dimensions of the model of a multistoreyed building are lm by 60 cm by 1.20 m. If the scale factor is 1 : 50,. find the actual
dimensions of the building. Also, find :
(i) the floor area of a room of the building, if the floor area of the corresponding room in the model is 50 sq cm.
(ii) the space (volume) inside a room of the model, if the space inside the corresponding room of the building is 90m3.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 121

Question 20.
In ∆ABC, ∠ACB = 90° and CD ⊥ AB. Prove that : \(\frac{\mathrm{BC}^{2}}{\mathrm{AC}^{2}}=\frac{\mathrm{BD}}{\mathrm{AD}}\).
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 122

Question 21.
A triangle ABC with AB = 3 cm, BC = 6 cm and AC = 4 cm is enlarged to ∆DEF such that the longest side of ∆DEF = 9 cm. Find the scale factor and hence, the lengths of the other sides of ∆DEF.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 123

Question 22.
Two isosceles triangles have equal vertical angles. Show that the triangles are similar.
If the ratio between the areas of these two triangles is 16 : 25, find the ratio between their corresponding altitudes.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 124

Question 23.
In ∆ABC, AP: PB = 2 :3. PO is parallel to BC and is extended to Q so that CQ is parallel to BA.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 125
Find:
(i) area ∆APO: area ∆ABC.
(ii) area ∆APO: area ∆CQO.
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 126

Question 24.
The following figure shows a triangle ABC in which AD and BE are perpendiculars to BC and AC respectively.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 127
Show that:
(i) ∆ADC – ∆BEC
(ii) CA × CE = CB × CD
(iii) ∆ ABC – ∆DEC
(iv) CD × AB = CA × DE
Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 128

Question 25.
In the given figure, ABC is a triangle-with ∠EDB = ∠ACB.
Prove that ∆ABC ~ ∆EBD.
If BE=6 cm, EC = 4 cm,
BD = 5 cm and area of
∆BED = 9 cm2. Calculate the
(i) length of AB
(ii) area of ∆ABC
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Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 130

Question 26.
In the given figure, ABC is a right-angled triangle with ZBAC = 90°.
(i) Prove ∆ADB ~ ∆CDA.
(ii) If BD = 18 cm, CD = 8 cm, find AD.
(iii) Find the ratio of the area of ∆ADB is to area of ∆CDA.
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Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 133

Question 27.
In the given figure, AB and DE are perpendicular to BC.
(i) Prove that ∆ABC ~ ∆DEC
(ii) If AB = 6 cm: DE = 4 cm and AC = 15 cm. Calculate CD.
(iii) Find the ratio of the area of ∆ABC : area of ∆DEC.
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Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 174

(ii)
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(iii)
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Question 28.
ABC is a right angled triangle with ∠ABC = 90°. D is any point on AB and DE is perpendicular to AC. Prove that:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 135
(i) ∆ADE ~ ∆ACB.
(ii) If AC = 13 cm, BC = 5 cm and AE=4 cm. Find DEandAD.
(iii) Find, area of ∆ADE : area of quadrilateral BCED. (2015)
Solution:
(i)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 176

(ii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 178

(iii)
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 179

Question 29.
Given: AB // DE and BC // EF. Prove that:
(i) \(\frac{\mathrm{AD}}{\mathrm{DG}}=\frac{\mathrm{CF}}{\mathrm{FG}}\)
(ii) ∆DFG ~ ∆ACG.
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Solution:
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 137

Question 30.
Selina Concise Mathematics Class 10 ICSE Solutions Similarity image - 180

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Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations

Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations (Including Number Lines)

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Linear Inequations Exercise 15A – Selina Concise Mathematics Class 8 ICSE Solutions

Question 1.
If the replacement set is the set of natural numbers, solve.
(i) x – 5 < 0
(ii) x + 1 < 7
(iii) 3x – 4 > 6
(iv) 4x + 1 > 17
Solution:
(i) x – 5 < 0
x – 5 + 5 <0 + 5 ………(Adding 5)
=> x < 5
Required answer = {1, 2, 3, 4}
(ii) x + 1 ≤ 7 => x + 1 – 1 ≤ 7 – 1 (Subtracting 1)
=> x ≤ 6
Required answer = {1, 2, 3, 4, 5, 6}
(iii) 3x – 4 > 6
3x – 4 + 4 > 6 + 4 (Adding 4)
=> 3x > 10
\(\frac { 3x }{ 3 }\) > \(\frac { 10 }{ 3 }\) …(Dividing by 3)
=> x > \(\frac { 10 }{ 3 }\)
=> x > \(3\frac { 1 }{ 3 }\)
Required answer = { 4, 5, 6, …}
(iv) 4x + 1 ≥ 17
=> 4x + 1 – 1 ≥ 17 – 1 (Subtracting)
=> 4x ≥ 16
=> \(\frac { 4x }{ 4 }\) ≥ \(\frac { 16 }{ 4 }\) (Dividing by 4)
=> x ≥ 4
Required answer = {4, 5, 6, …}

Question 2.
If the replacement set = {-6, -3, 0, 3, 6, 9}; find the truth set of the following:
(i) 2x – 1 > 9
(ii) 3x + 7 < 1
Solution:
(i) 2x – 1 > 9
⇒ 2x – 1 + 1 > 9 + 1 (Adding 1)
⇒ 2x > 10
⇒ x > 5 (Dividing by 2)
⇒ x > 5
Required answer = {6, 9}
(ii) 3x + 7 ≤ 1
⇒ 3x + 7 – 7 ≤ 1 – 7 (Subtracting 7)
⇒ 3x ≤ – 6
⇒ x ≤ – 2
Required Answer = {-6, -3}

Question 3.
Solve 7 > 3x – 8; x ∈ N
Solution:
7 > 3x – 8
=> 7 – 3x > 3x – 3x – 8 (Subtracting 3x)
=> 7 – 7 – 3x > 3x – 3x – 8 – 7 (Subtracting 7)
=> -3x > -15
=> x < 5 (Dividing by -3)
Required Answer = {1, 2, 3, 4}
Note : Division by negative number reverses the inequality.

Question 4.
-17 < 9y – 8 ; y ∈ Z
Solution:
-17 < 9y – 8
=> -17 + 8 < 9y – 8 + 8 (Adding 8)
=> -9 < 9y
=> -1 < y (Dividing by 9)
Required number = {0, 1, 2, 3, 4, …}

Question 5.
Solve 9x – 7 ≤ 28 + 4x; x ∈ W
Solution:
9x – 1 ≤ 28 + 4x
=> 9x – 4x – 7 ≤ 28 + 4x – 4x (Subtracting 4x)
=> 5x – 7 ≤ 28
=> 5x – 7 + 7 ≤ 28 + 7 (Adding 7)
=> 5x ≤ 35
=> x ≤ 7 (Dividing by 5)
Required answer = {0, 1, 2, 3, 4, 5, 6, 7}

Question 6.
Solve : \(\frac { 2 }{ 3 }\)x + 8 < 12 ; x ∈ W
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -1

Question 7.
Solve -5 (x + 4) > 30 ; x ∈ Z
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -2

Question 8.
Solve the inquation 8 – 2x > x – 5 ; x ∈ N.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -3
x = 1, 2, 3, 4 (x ∈ N)
Solution set = {1, 2, 3, 4}

Question 9.
Solve the inequality 18 – 3 (2x – 5) > 12; x ∈ W.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -4

Question 10.
Solve : \(\frac { 2x+1 }{ 3 }\) + 15 < 17; x ∈ W.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -5

Question 11.
Solve : -3 + x < 2, x ∈ N
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -6

Question 12.
Solve : 4x – 5 > 10 – x, x ∈ {0, 1, 2, 3, 4, 5, 6, 7}
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -7
Solution set = {4, 5, 6, 7}
Question 13.
Solve : 15 – 2(2x – 1) < 15, x ∈ Z.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -8

Question 14.
Solve : \(\frac { 2x+3 }{ 5 }\) > \(\frac { 4x-1 }{ 2 }\) , x ∈ W.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -9

Linear Inequations Exercise 15B – Selina Concise Mathematics Class 8 ICSE Solutions

Solve and graph the solution set on a number line :
Question 1.
x – 5 < -2 ; x ∈ N
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -10

Question 2.
3x – 1 > 5 ; x ∈ W
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -11

Question 3.
-3x + 12 < -15 ; x ∈ R.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -12

Question 4.
7 > 3x – 8 ; x ∈ W
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -13

Question 5.
8x – 8 < – 24 ; x ∈ Z
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -14
ematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -15

Question 6.
8x – 9 > 35 – 3x ; x ∈ N
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -16

Question 7.
5x + 4 > 8x – 11 ; x ∈ Z
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -17

Question 8.
\(\frac { 2x }{ 5 }\) + 1 < -3 ; x ∈ R
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -18
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -19

Question 9.
\(\frac { x }{ 2 }\) > -1 + \(\frac { 3x }{ 4 }\) ; x ∈ N
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -20

Question 10.
\(\frac { 2 }{ 3 }\) x + 5 ≤ \(\frac { 1 }{ 2 }\) x + 6 ; x ∈ W
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -21
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -22

Question 11.
Solve the inequation 5(x – 2) > 4 (x + 3) – 24 and represent its solution on a number line.
Given the replacement set is {-4, -3, -2, -1, 0, 1, 2, 3, 4}.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -23

Question 12.
Solve \(\frac { 2 }{ 3 }\) (x – 1) + 4 < 10 and represent its solution on a number line.
Given replacement set is {-8, -6, -4, 3, 6, 8, 12}.
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -24
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -25

Question 13.
For each inequation, given below, represent the solution on a number line :
(i) \(\frac { 5 }{ 2 }\) – 2x ≥ \(\frac { 1 }{ 2 }\) ; x ∈ W
(ii) 3(2x – 1) ≥ 2(2x + 3), x ∈ Z
(iii) 2(4 – 3x) ≤ 4(x – 5), x ∈ W
(iv) 4(3x + 1) > 2(4x – 1), x is a negative integer
(v) \(\frac { 4 – x }{ 2 }\) < 3, x ∈ R
(vi) -2(x + 8) ≤ 8, x ∈ R
Solution:
Selina Concise Mathematics Class 8 ICSE Solutions Chapter 15 Linear Inequations image -26
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