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R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE chapter 7 - Ratio and Proportion [Latest edition]

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Chapters

UNIT 1: COMMERCIAL MATHEMATICS

    1: Goods and Services Tax (G.S.T.)

    2: Banking

    3: Shares and Dividends

UNIT 2: ALGEBRA

    4: Linear Inequations

    5: Quadratic Equation

    6: Problems on Quadratic Equations

▶ 7: Ratio and Proportion

   Chapter 8: Remainder Theorem and Factor Theorem

    9: Matrices

   Chapter 10: Arithmetic Progression

   Chapter 11: Geometric Progression

    12: Reflection

   Chapter 13: Section and Mid-point Formulae

   Chapter 14: Equation of a Straight Line

UNIT 3: GEOMETRY

   Chapter 15: Similarity (As a Size Transformation)

   Chapter 16: Similarity of Triangles

    17: Loci

   Chapter 18: Angle and Cyclic Properties of a Circle

   Chapter 19: Tangent Properties of Circles

    20: Constructions

UNIT 4: MENSURATION

   Chapter 21: Volume and Surface Area of Solids (Cylinder, Cone and Sphere)

UNIT 5: TRIGONOMETRY

   Chapter 22: Trigonometrical Identities

   Chapter 23: Heights and Distances

UNIT 6: STATISTICS

   Chapter 24: Graphical Representation of Statistical Data

   Chapter 25: Measures of Central Tendency (Mean)

   Chapter 26: Median, Quartiles and Mode

UNIT 7: PROBABILITY

   Chapter 27: Probability

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE chapter 7 - Ratio and Proportion - Shaalaa.com
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Solutions for Chapter 7: Ratio and Proportion

Below listed, you can find solutions for Chapter 7 of CISCE R.S. Aggarwal for Mathematics [English] Class 10 ICSE.


EXERCISE 7AEXERCISE 7BEXERCISE 7CCOMPETENCY-FOCUSED QUESTIONS
EXERCISE 7A [Pages 93 - 95]

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE 7 Ratio and Proportion EXERCISE 7A [Pages 93 - 95]

1. (i)Page 93

Find the ratio between 60 paise and ₹ 1.35

1. (ii)Page 93

Find the ratio between 1.8 m and 75 cm

1. (iii)Page 93

Find the ratio between 1.5 kg and 600 g

1. (iv)Page 93

Find the ratio between 35 min and $$1\frac{3}{4}$$ hrs

2. (i)Page 93

If A : B = 5 : 6 and B : C = 9 : 11, find A : C.

2. (ii)Page 93

If A : B = 5 : 6 and B : C = 9 : 11, find A : B : C.

3. (i)Page 93

If $$\mathrm{P}:\mathrm{Q} = 7 : 4$$ and $$\mathrm{Q}:\mathrm{R} = 5 : 14$$, find $$\mathrm{R}:\mathrm{P}$$.

3. (ii)Page 93

If $$\mathrm{P}:\mathrm{Q} = 7 : 4$$ and $$\mathrm{Q}:\mathrm{R} = 5 : 14$$, find $$\mathrm{P}:\mathrm{Q}:\mathrm{R}$$.

4.Page 93

If $$3\mathrm{A} = 5\mathrm{B} = 6\mathrm{C}$$, find $$\mathrm{A}:\mathrm{B}:\mathrm{C}$$.

5.Page 93

If $$\frac{\mathrm{A}}{2} = \frac{\mathrm{B}}{3} = \frac{\mathrm{C}}{6}$$, find A : B : C.

6.Page 93

If $$a : b = 8 : 5$$, find $$(7a + 5b) : (8a - 9b)$$.

7.Page 93

If $$x : y = 3 : 2$$, find $$(5x - 3y) : (7x + 2y)$$.

8.Page 93

If $$x : y = 10 : 3$$, find $$(3x^{2} + 2y^{2}) : (3x^{2} - 2y^{2})$$.

9.Page 93

If $$a : b = 2 : 5$$, find $$(3a^2 - 2ab + 5b^2) : (a^2 + 7ab - 2b^2)$$.

10.Page 93

If $$(5x + 2y) : (7x + 4y) = 13 : 20$$, find $$x : y$$.

11.Page 93

If $$(3x + 5y) : (3x - 5y) = 7 : 3$$, find $$x : y$$.

12.Page 94

If $$(6x^2 - xy) : (2xy - y^2) = 6 : 1$$, find $$x : y$$.

13.Page 94

If $$(4x^2 - 3y^2) : (2x^2 + 5y^2) = 12 : 19$$, find $$x : y$$.

14.Page 94

If $$x^2 + 4y^2 = 4xy$$, find $$x : y$$.

15.Page 94

If $$10x^2 - 23xy + 9y^2 = 0$$, find $$x : y$$.

16.Page 94

A ratio is equal to $$3 : 4$$. If its consequent is 144, what is its antecedent?

17.Page 94

Two numbers are in the ratio $$8 : 13$$. If 14 is added to each of the numbers, the ratio becomes $$2 : 3$$. Find the numbers.

18.Page 94

Two numbers are in the ratio $$5 : 7$$. If 8 is subtracted from each, the ratio becomes $$3 : 5$$. Find the numbers.

19.Page 94

What least number must be added to each term of the ratio $$5 : 7$$ to make it $$8 : 9$$?

20.Page 94

Out of the monthly income of ₹45000, Rahul spends ₹31500 and the rest he saves. Find the ratio of his

  1. income to expenditure 
  2. income to savings 
  3. savings to expenditure.
21.Page 94

The cost of making an umbrella is divided between material, labour and overheads in the ratio $$6 : 4 : 1$$. If the material costs ₹132, find the cost of production of an umbrella.

22.Page 94

Divide ₹6720 in the ratio $$5 : 3$$.

23.Page 94

Divide ₹11620 among A, B and C in the ratio $$35 : 28 : 20$$.

24.Page 94

Divide ₹782 among P, Q and R in the ratio $$\frac{1}{2} : \frac{2}{3} : \frac{3}{4}$$.

[Hint : Given ratio = 6 : 8 : 9.]

25.Page 94

If ₹5100 be divided among A, B, C in such a way that A gets $$\frac{2}{3}$$ of what B gets and B gets $$\frac{1}{4}$$ of what C gets, find their respective shares.

26.Page 94

Divide ₹8300 among A, B and C such that 4 times A's share, 5 times B's share and 7 times C's share may all be equal.

27.Page 94

A sum of money is divided between A and B in the ratio $$6 : 11$$. If B's share is ₹7315, find (i) A's share (ii) the total amount of money.

28.Page 94

The ages of Tanvy and Divya are in the ratio $$5 : 7$$. Five years hence, their ages will be in the ratio $$3 : 4$$. Find their present ages.

29.Page 94

One year ago, the ratio of Amit’s and Arun’s ages was $$6 : 7$$ respectively. Four years hence, their ages will be in the ratio $$7 : 8$$. How old is Amit?

30.Page 94

Reena reduces her weight in the ratio $$5 : 4$$. What is her weight now, if originally it was $$70 \text{ kg}$$?

31.Page 94

$$68 \text{ kg}$$ of a mixture contains milk and water in the ratio $$27 : 7$$. How much more water is to be added to this mixture to get a new mixture containing milk and water in the ratio $$3 : 1$$?

32.Page 94

A mixture contains milk and water in the ratio $$5 : 1$$. On adding 5 litres of water, the ratio of milk to water becomes $$5 : 2$$. Find the quantity of milk in the original mixture.

33.Page 94

In an examination, the ratio of passes to failures was $$4 : 1$$. Had 30 less appeared and 20 less passed, the ratio of passes to failures would have been $$5 : 1$$. How many students appeared for the examination?

34.Page 94

Find the angles of a triangle which are in the ratio $$5 : 4 : 3$$.

35.Page 94

The sides of a triangle are in the ratio $$\frac{1}{2} : \frac{1}{3} : \frac{1}{4}$$ and its perimeter is $$91 \text{ cm}$$. Find the lengths of the sides of the triangle.

36.Page 94

In a school, the boys and girls are in the ratio $$9 : 5$$. If there are 425 girls, what is the total number of students in the school?

37. (i)Page 95

Compare the following ratios: 

(7 : 9) and (11 : 16) 

37. (ii)Page 95

Compare the following ratios: 

(19 : 25) and (17 : 20)

37. (iii)Page 95

Compare the following ratios: 

$$\left(\frac{1}{2} : \frac{1}{5}\right)$$ and (5 : 2)

38. (i)Page 95

Arrange the following ratios in descending order of magnitude: 

(5 : 6), (8 : 9), (13 : 18) and (19 : 24)

38. (ii)Page 95

Arrange the following ratios in descending order of magnitude: 

(6 : 7), (13 : 14), (19 : 21) and (23 : 28)

38. (iii)Page 95

Arrange the following ratios in descending order of magnitude: 

(7 : 12), (9 : 16), (13 : 20) and (5 : 8)

39. (i)Page 95

Arrange the following ratios in ascending order of magnitude:

(4 : 9), (6 : 11), (7 : 13) and (27 : 50)

39. (ii)Page 95

Arrange the following ratios in ascending order of magnitude: 

(2 : 3), (8 : 15), (11 : 12) and (7 : 16)

39. (iii)Page 95

Arrange the following ratios in ascending order of magnitude:

(3 : 5), (4 : 9), (5 : 11) and (10 : 17)

40.Page 95

If (3a + 2b) : (5a + 3b) = 18 : 29. Find a : b

EXERCISE 7B [Pages 103 - 105]

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE 7 Ratio and Proportion EXERCISE 7B [Pages 103 - 105]

1. (i)Page 103

Find $$x$$, when $$3 : 4 :: 2.4 : x$$.

1. (ii)Page 103

Find $$x$$, when $$1:3::x:7$$.

1. (iii)Page 103

Find $$x$$, when $$x : 1.5 :: 3 : 5$$.

2. (i)Page 103

Find the fourth proportional to 3, 8 and 21.

2. (ii)Page 103

Find the fourth proportional to 1.4, 3.2 and 7.

2. (iii)Page 103

Find the fourth proportional to 1.5, 4.5 and 3.6.

2. (iv)Page 103

Find the fourth proportional to $$a^2$$, $$ab$$ and $$b^2$$.

2. (v)Page 103

Find the fourth proportional to $$(a^2 - ab + b^2)$$, $$(a^3 + b^3)$$ and $$(a - b)$$.

3. (i)Page 103

Find the third proportional to 9 and 6.

3. (ii)Page 103

Find the third proportional to `2 2/3` and 4

3. (iii)Page 103

Find the third proportional to 1.6 and 2.4.

3. (iv)Page 103

Find the third proportional to $$(2 + \sqrt{3})$$ and $$(5 + 4\sqrt{3})$$.

3. (v)Page 103

Find the third proportional to $$\left(\frac{a}{b} +\frac{b}{a}\right)$$ and $$\sqrt{a^2 + b^2}$$.

4. (i)Page 103

Find the mean proportion between 28 and 63.

4. (ii)Page 103

Find the mean proportion between 2.5 and 0.9.

4. (iii)Page 103

Find the mean proportion between 6.25 and 1.6.

4. (iv)Page 103

Find the mean proportion between $$(\sqrt{26} - \sqrt{17})$$ and $$(\sqrt{26} + \sqrt{17})$$.

4. (v)Page 103

Find the mean proportional between `6 + 3sqrt(3)` and `8 - 4sqrt(3)`

5.Page 103

6 is the mean proportion between two numbers x and y and 48 is the third proportional of x and y. Find the numbers.

6.Page 103

What least number must be added to each of the numbers 5, 11, 19 and 37, so that the resulting numbers are proportional.

7.Page 103

What number must be added to each of the numbers 4, 6, 8, 11 in order to get the four numbers in proportion?

8.Page 103

What least number must be subtracted from each of the numbers 23, 30, 57 and 78, so that the remainders are in proportion?

9.Page 103

If $$(x - 2)$$, $$(x + 2)$$, $$(2x + 1)$$ and $$(2x + 19)$$ are in proportion, find the value of $$x$$.

10.Page 103

The following numbers, K + 3, K + 2, 3K – 7 and 2K – 3 are in proportion. Find k. 

11.Page 103

If $$(x + 5)$$ is the geometric mean between $$(x + 2)$$ and $$(x + 9)$$, find the value of $$x$$.

12.Page 103

Find two numbers whose mean proportion is 36 and the third proportional is 288.

13. (i)Page 103

If $$a : b :: c : d$$, prove that $$(a^2 + ab) : (c^2 + cd) = (b^2 - 2ab) : (d^2 - 2cd)$$.

13. (ii)Page 103

If $$a : b :: c : d$$, prove that $$(a^2 + b^2) : (c^2 + d^2) = (ab + ad - bc) : (cd - ad + bc)$$.

13. (iii)Page 103

If $$a : b :: c : d$$, prove that $$(a^2 + ac + c^2) : (a^2 - ac + c^2) = (b^2 + bd + d^2) : (b^2 - bd + d^2)$$.

14. (i)Page 103

If $$a : b :: c : d$$, show that $$\frac{a + b}{c + d} = \frac{\sqrt{2a^2 + 7b^2}}{\sqrt{2c^2 + 7d^2}}$$.

14. (ii)Page 103

If $$a : b :: c : d$$, show that $$\frac{ma^2 + nc^2}{mb^2 + nd^2} = \frac{\sqrt{a^4 + c^4}}{\sqrt{b^4 + d^4}}$$.

14. (iii)Page 103

If $$a : b :: c : d$$, show that $$\frac{a^2 + ab + b^2}{a^2 - ab + b^2} = \frac{c^2 + cd + d^2}{c^2 - cd + d^2}$$.

14. (iv)Page 103

If $$a : b :: c : d$$, show that $$\frac{(a + c)^3}{(b + d)^3} = \frac{a(a - c)^2}{b(b - d)^2}$$.

[Hint : Use k-method.]

15. (i)Page 104

If $$\frac{x}{a} = \frac{y}{b} = \frac{z}{c}$$, prove that $$\frac{x^2 + y^2 + z^2}{a^2 + b^2 + c^2} = \left(\frac{px + qy + rz}{pa + qb + rc}\right)^2$$.

15. (ii)Page 104

If $$\frac{x}{a} = \frac{y}{b} = \frac{z}{c}$$, prove that $$\frac{x^3}{a^3} + \frac{y^3}{b^3} + \frac{z^3}{c^3} = \frac{3xyz}{abc}$$.

15. (iii)Page 104

If $$\frac{x}{a} = \frac{y}{b} = \frac{z}{c}$$, prove that $$\frac{x^3}{a^2} + \frac{y^3}{b^2} + \frac{z^3}{c^2} = \frac{(x + y + z)^3}{(a + b + c)^2}$$.

15. (iv)Page 104

If $$\frac{x}{a} = \frac{y}{b} = \frac{z}{c}$$, prove that $$\frac{ax - by}{(a + b)(x - y)} + \frac{by - cz}{(b + c)(y - z)} + \frac{cz - ax}{(c + a)(z - x)} = 3$$.

[Hint : Use k-method in each.]

16. (i)Page 104

If $$\frac{a}{b} = \frac{c}{d} = \frac{e}{f}$$, prove that $$(b^2 + d^2 + f^2)(a^2 + c^2 + e^2) = (ab + cd + ef)^2$$.

16. (ii)Page 104

If $$\frac{a}{b} = \frac{c}{d} = \frac{e}{f}$$ prove that $$\frac{a^3 + c^3 + e^3}{b^3 + d^3 + f^3} = \frac{ace}{bdf}$$.

16. (iii)Page 104

If $$\frac{a}{b} = \frac{c}{d} = \frac{e}{f}$$ prove that $$\left(\frac{a^2}{b^2} + \frac{c^2}{d^2} + \frac{e^2}{f^2}\right) = \left(\frac{ac}{bd} + \frac{ce}{df} + \frac{ae}{bf}\right)$$

16. (iv)Page 104

If $$\frac{a}{b} = \frac{c}{d} = \frac{e}{f}$$ prove that $$(bdf) \cdot \left(\frac{a + b}{b} + \frac{c + d}{d} + \frac{e + f}{f}\right)^3 = 27(a + b)(c + d)(e + f)$$.

[Hint : Use k-method in each.]

17. (i)Page 104

If a, b, c are in continued proportion, prove that: `(a + b)/(b + c) = (a^2(b - c))/(b^2(a - b)`.

17. (ii)Page 104

If $$a, b, c$$ are in continued proportion, prove that $$\frac{a + b + c}{a - b + c} = \frac{(a + b + c)^2}{(a^2 + b^2 + c^2)}$$.

17. (iii)Page 104

If $$a, b, c$$ are in continued proportion, prove that $$\frac{a^2 + ab + b^2}{b^2 + bc + c^2} = \frac{a}{c}$$.

17. (iv)Page 104

If $$a, b, c$$ are in continued proportion, prove that $$(a + b + c)(a - b + c) = (a^2 + b^2 + c^2)$$.

17. (v)Page 104

If $$a, b, c$$ are in continued proportion, prove that $$a^2b^2c^2(a^{-3} + b^{-3} + c^{-3}) = (a^3 + b^3 + c^3)$$.

17. (vi)Page 104

If $$a, b, c$$ are in continued proportion, prove that $$ad(c^2 + d^2) = c^3(b + d)$$.

\[ [\textbf{Hint :}\ \dfrac{a}{b} = \dfrac{b}{c} = k \Rightarrow b = ck \ \textit{and} \ a = ck^{2}\,] \]

18.Page 104

If x, y and z are in continued proportion, Prove that:

`x/(y^2.z^2) + y/(z^2.x^2) + z/(x^2.y^2) = 1/x^3 + 1/y^3 + 1/z^3`

19. (i)Page 104

If $$a, b, c, d$$ are in continued proportion, prove that $$(b + c)(b + d) = (c + a)(c + d)$$.

19. (ii)Page 104

If $$a, b, c, d$$ are in continued proportion, prove that $$(a + b)(b + c) - (a + c)(b + d) = (b - c)^2$$.

19. (iii)Page 104

If $$a, b, c, d$$ are in continued proportion, prove that $$(a^2 - b^2)(c^2 - d^2) = (b^2 - c^2)^2$$.

19. (iv)Page 104

If $$a, b, c, d$$ are in continued proportion, prove that $$\left(\frac{a - b}{c} + \frac{a - c}{b}\right)^2 - \left(\frac{d - b}{c} + \frac{d - c}{b}\right)^2 = (a - d)^2 \left(\frac{1}{c^2} + \frac{1}{b^2}\right)$$.

\[ [\textbf{Hint :}\ \dfrac{a}{b} = \dfrac{b}{c} = \dfrac{c}{d} = k \Rightarrow c = dk,\ b = dk^{2} \ \text{and} \ a = dk^{3}.\,] \]

20.Page 104

If $$ax = by = cz$$, prove that $$\frac{x^2}{yz} + \frac{y^2}{zx} + \frac{z^2}{xy} = \frac{bc}{a^2} + \frac{ca}{b^2} + \frac{ab}{c^2}$$.

\[ [\textbf{Hint :}\ ax = by = cz,\ \Rightarrow \ \dfrac{x}{bc} = \dfrac{y}{ca} = \dfrac{z}{ab} = k \Rightarrow x = kbc,\ y = kca \ \textit{and} \ z = kab.] \]

21.Page 104

If $$\frac{x}{b + c - a} = \frac{y}{c + a - b} = \frac{z}{a + b - c}$$, prove that each ratio is equal to $$\left(\frac{x + y + z}{a + b + c}\right)$$. Also, show that $$(b - c)x + (c - a)y + (a - b)z = 0$$.

\[ \begin{array}{l} [\textbf{Hint :}\ \text{Each ratio} = \dfrac{x + y + z}{(b + c - a) + (c + a - b) + (a + b - c)} = \dfrac{x + y + z}{a + b + c}. \\[16pt] \text{Let each ratio be equal to } k\text{. Then,} \\[8pt] x = (b + c - a)k,\ y = (c + a - b)k \ \text{and} \ z = (a + b - c)k.] \end{array} \]

22.Page 105

If $$b$$ is the mean proportion between $$a$$ and $$c$$, show that $$\frac{a^4 + a^2b^2 + b^4}{b^4 + b^2c^2 + c^4} = \frac{a^2}{c^2}$$.

[Hint : Substitute \[b^{2} = ac\] in L.H.S. to get R.H.S.]

EXERCISE 7C [Pages 112 - 113]

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE 7 Ratio and Proportion EXERCISE 7C [Pages 112 - 113]

1.Page 112

If $$a : b = c : d$$, prove that $$(9a + 13b) : (9a - 13b) = (9c + 13d) : (9c - 13d)$$.

2.Page 112

If $$a : b = c : d$$, prove that $$(3a + 2b) : (3a - 2b) = (3c + 2d) : (3c - 2d)$$.

3.Page 112

If $$(3a + 5b) : (3a - 5b) = (3c + 5d) : (3c - 5d)$$, prove that $$a : b = c : d$$.

4.Page 112

If $$(4a^2 + 7b^2) : (4a^2 - 7b^2) = (4c^2 + 7d^2) : (4c^2 - 7d^2)$$, prove that $$a : b = c : d$$.

5.Page 112

If $$(ma + nb) : (mc + nd) = (ma - nb) : (mc - nd)$$, prove that $$a : b = c : d$$.

6.Page 112

If $$\frac{5x + 6y}{5x - 6y} = \frac{5u + 6v}{5u - 6v}$$ show that $$\frac{x}{y} = \frac{u}{v}$$.

[Hint : We have $$\frac{5x + 6y}{5x - 6y} = \frac{5u + 6v}{5u - 6v}$$. Apply Componendo & Dividendo.]

7.Page 112

If $$x = \frac{6ab}{a + b}$$, prove that $$\left(\frac{x + 3a}{x - 3a} + \frac{x + 3b}{x - 3b}\right) = 2$$.

[Hint : We have $$\frac{x}{3a} = \frac{2b}{a + b}$$ and $$\frac{x}{3b} = \frac{2a}{a + b}$$. Apply Componendo & Dividendo on each.]

8.Page 112

If $$\frac{x^3 + 3x}{3x^2 + 1} = \frac{341}{91}$$, prove that $$x = 11$$.

[Hint : By componendo and dividendo, $$\frac{(x + 1)^3}{(x - 1)^3} = \frac{432}{250} = \frac{216}{125} = \left(\frac{6}{5}\right)^3 \Rightarrow \frac{x + 1}{x - 1} = \frac{6}{5}$$]

9.Page 112

If $$\frac{\sqrt{x + 2} + \sqrt{x - 3}}{\sqrt{x + 2} - \sqrt{x - 3}} = 5$$, prove that $$x = 7$$.

10.Page 112

If $$\frac{\sqrt{x + 5} + \sqrt{x - 16}}{\sqrt{x + 5} - \sqrt{x - 16}} = \frac{7}{3}$$, prove that $$x = 20$$.

11. (i)Page 112

If $$\frac{\sqrt{3x} + \sqrt{2x - 1}}{\sqrt{3x} - \sqrt{2x - 1}} = 5$$, prove that $$x = \frac{3}{2}$$.

11. (ii)Page 112

Using properties of proportion, solve for $$x$$. Given that $$x$$ is positive:

$$\frac{2x + \sqrt{4x^2 - 1}}{2x - \sqrt{4x^2 - 1}} = 4$$

12.Page 112

Using properties of proportion solve for $$x$$, given $$\frac{\sqrt{5x} + \sqrt{2x - 6}}{\sqrt{5x} - \sqrt{2x - 6}} = 4$$.

13.Page 112

Using componendo and dividendo solve for x:

`(sqrt(2x + 2) + sqrt(2x - 1))/(sqrt(2x + 2) - sqrt(2x - 1))` = 3

14.Page 112

If $$16\left(\frac{a - x}{a + x}\right)^3 = \left(\frac{a + x}{a - x}\right)$$, prove that $$x = \frac{a}{3}$$.

\[ [\textbf{Hint :}\ \text{We have}\ \left( \dfrac{a + x}{a - x} \right)^{4} = 16 = 2^{4} \Rightarrow \dfrac{a + x}{a - x} = 2.\,] \]

15.Page 113

If `(a + b)^3/(a - b)^3 = 64/27`

  1. Find `(a + b)/(a - b)`
  2. Hence using properties of proportion, find a : b.
16. (i)Page 113

If x = `(sqrt(2a + 1) + sqrt(2a - 1))/(sqrt(2a + 1) - sqrt(2a - 1))` prove that x2 − 4ax + 1 = 0

16. (ii)Page 113

If $$x = \frac{\sqrt{b+3a} + \sqrt{b-3a}}{\sqrt{b+3a} - \sqrt{b-3a}}$$, prove that $$3ax^2 - 2bx + 3a = 0$$.

17.Page 113

If $$\frac{\sqrt{2a+3b} + \sqrt{2a-3b}}{\sqrt{2a+3b} - \sqrt{2a-3b}}$$ prove that $$3bx^2 - 4ax + 3b = 0$$.

18.Page 113

If $$x = \frac{\sqrt[3]{m+1} + \sqrt[3]{m-1}}{\sqrt[3]{m+1} - \sqrt[3]{m-1}}$$, prove that $$x^3 - 3x^2m + 3x - m = 0$$.

\[ \begin{array}{l} [\textbf{Hint :}\ \text{By componendo and dividendo, we have}\ \dfrac{x + 1}{x - 1} = \dfrac{\sqrt[3]{m + 1}}{\sqrt[3]{m - 1}} \Leftrightarrow \dfrac{(x + 1)^{3}}{(x - 1)^{3}} = \dfrac{m + 1}{m - 1}. \\[16pt] \text{Now, apply componendo and dividendo.}] \end{array} \]

19.Page 113

What quantity must be added to each term of the ratio $$a : b$$ to make it $$(c : d)$$?

20.Page 113

If $$\frac{a+3b+2c+6d}{a-3b+2c-6d} = \frac{a+3b-2c-6d}{a-3b-2c+6d}$$, prove that $$\frac{a}{b} = \frac{c}{d}$$.

\[ \begin{array}{l} \left[ \textbf{Hint :}\ \text{We have}\ \dfrac{(a + 3b) + (2c + 6d)}{(a + 3b) - (2c + 6d)} = \dfrac{(a - 3b) + (2c - 6d)}{(a - 3b) - (2c - 6d)} \right. \\[16pt] \text{Now apply componendo and dividendo.}] \end{array} \]

21.Page 113

If $$\frac{2a+2b-3c-3d}{2a-2b-3c+3d} = \frac{a+b-4c-4d}{a-b-4c+4d}$$, prove that $$\frac{a}{b} = \frac{c}{d}$$.

\[ \begin{array}{l} \left[ \textbf{Hint :}\ \text{We have}\ \dfrac{(2a - 3c) + (2b - 3d)}{(2a - 3c) - (2b - 3d)} = \dfrac{(a - 4c) + (b - 4d)}{(a - 4c) - (b - 4d)} \right. \\[16pt] \text{Now apply componendo and dividendo.}] \end{array} \]

22.Page 113

If $$(a+b+c+d) : (a+b-c-d) = (a-b+c-d) : (a-b-c+d)$$, prove that $$a : b = c : d$$.

\[ \begin{array}{l} [\textbf{Hint :}\ \text{We have}\ \dfrac{(a + b) + (c + d)}{(a + b) - (c + d)} = \dfrac{(a - b) + (c - d)}{(a - b) - (c - d)}. \\[16pt] \text{Now apply componendo and dividendo.}] \end{array} \]

23.Page 113

Given : $$\frac{x^3+12x}{6x^2+8} = \frac{y^3+27y}{9y^2+27}$$. Using componendo, find $$x : y$$. 

24.Page 113

Using properties of proportion, find x : y, if `(x^2 + 2x)/(2x + 4) = (y^2 + 3y)/(3y + 9)`

25.Page 113

Using properties of proportion, find the value of ‘x’:

`(6x^2 + 3x − 5)/(3x − 5) = (9x^2 + 2x + 5)/(2x + 5); x ≠ 0`

COMPETENCY-FOCUSED QUESTIONS [Pages 114 - 118]

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE 7 Ratio and Proportion COMPETENCY-FOCUSED QUESTIONS [Pages 114 - 118]

I. Multiple Choice Questions Choose the correct alternative :

1.Page 114

Which of the following is the ratio between a number and the number obtained by adding one-fifth of that number to it?

  • 4 : 5

  • 5 : 4

  • 5 : 6

  • 6 : 5

2.Page 114

Govind spends ₹8100 in buying some jeans at ₹1200 each and some shirts at ₹300 each. The ratio of the number of shirts to that of jeans, when the maximum possible number of jeans is purchased is ______. 

  • 1 : 2

  • 1 : 4

  • 2 : 1

  • 5 : 7

3.Page 114

Which of the following represents xy = 64?

  • 8 : x = 8 : y

  • x : 16 = y : 4

  • x : 8 = y : 8

  • 32 : x = y : 2

4.Page 114

If a carton, containing a dozen mirrors is dropped, then which of the following cannot be the ratio of broken mirrors to unbroken mirrors?

  • 2 : 1

  • 7 : 5

  • 3 : 2

  • 3 : 1

5.Page 114

A mixture of paint is prepared by mixing 2 parts of red pigments with 5 parts of the base. Using the given information in the following table, find the values of a, b and c to get the required mixture of paint.

Parts of red pigment 2 4 b 6
Parts of base 5 a 12.5 c
  • a = 10, b = 10, c = 10

  • a = 5, b = 2, c = 5

  • a = 10, b = 5, c = 10

  • a = 10, b = 5, c = 15

6.Page 114

If (x + 1) : 8 = 3.75 : 7, then the value of x is ______.

  • `1 2/7`

  • `2 2/7`

  • `3 2/7`

  • `4 2/7`

7.Page 114

If `sqrt(2) : (1 + sqrt(3)) :: sqrt(6) : x`, then x is equal to ______.

  • `sqrt(3) + 3`

  • `1 - sqrt(3)`

  • `sqrt(3) - 3`

  • `1 + sqrt(3)`

8.Page 114

0.5 of a number is equal to 0.07 of another. The ratio of the numbers is ______.

  • 1 : 14

  • 5 : 7

  • 7 : 50

  • 50 : 7

9.Page 114

25% of x is equal to 35% of y, then x : y equals.

  • 5 : 7

  • 7 : 5

  • 13 : 15

  • 15 : 13

10.Page 114

If `A = 1/3 B` and `B = 1/2 C`, then A : B : C is equal to ______.

  • 1 : 2 : 6

  • 1 : 3 : 6

  • 1 : 2 : 3

  • 3 : 2 : 1

11.Page 114

If 2p = 3q = 4r then p : q : r is equal to ______.

  • 2 : 3 : 4

  • 3 : 4 : 6

  • 4 : 3 : 2

  • 6 : 4 : 3

12.Page 114

If `a/3 = b/4 = c/7`, then `(a + b + c)/c` = ?

  • `1/2`

  • `1/7`

  • 2

  • 7

13.Page 114

If x, 5.4, 5, 9 are in proportion, then x is equal to ______.

  • 3

  • 9.72

  • 25

  • `25/3`

14.Page 114

The fourth proportional to 5, 8, 15 is ______.

  • 18

  • 20

  • 21

  • 24

15.Page 114

The fourth proportional to 0.12, 0.21 and 8 is ______.

  • 8.9

  • 14

  • 17

  • 56

16.Page 115

The third proportional to 38 and 15 is ______.

  • `15 xx 15/38`

  • `38 xx 38/15`

  • `15 xx 15/38`

  • `38 xx 15/2`

17.Page 115

The third proportional to (x2 – y2) and (x – y) is ______.

  • `(x - y)/(x + y)`

  • `(x + y)/(x - y)`

  • (x + y)

  • (x – y)

18.Page 115

The mean proportion between 9 and 16 is ______.

  • 7

  • 12

  • 25

  • 144

19.Page 115

The mean proportion between 0.02 and 0.32 is ______.

  • 0.08

  • 0.16

  • 0.3

  • 0.34

20.Page 115

The mean proportion between `(3 + sqrt(2))` and `(12 - sqrt(32))` is ______.

  • 6

  • `2sqrt(7)`

  • `sqrt(7)`

  • `(15 - 3sqrt(2))/2`

21.Page 115

The mean proportion between x and y is 6. The third proportional to x and y is 48. Then x : y equals ______.

  • 1 : 3

  • 1 : 4

  • 1 : 6

  • 1 : 9

22.Page 115

The ratio between the third proportional to 12 and 30 and mean proportion of 9 and 25, is ______.

  • 2 : 1

  • 5 : 1

  • 7 : 15

  • 9 : 14

23.Page 115

When 30% of one number is subtracted from another number, the second number reduces to its four-fifths. What is the ratio of the first to the second number?

  • 2 : 5

  • 2 : 3

  • 4 : 7

  • cannot be determined

24.Page 115

Five mangoes and four guavas cost as much as three mangoes and seven guavas. What is the ratio of the cost of one mango to the cost of one guava?

  • 1 : 3

  • 3 : 2

  • 4 : 3

  • 5 : 2

25.Page 115

Of 132 examinees of a certain class, the ratio of passed to failed students is 9 : 2. If 4 more students passed, what would have been the ratio of passed to failed students?

  • 3 : 28

  • 28 : 5

  • 4 : 25

  • 25 : 4

26.Page 115

There are three boxes – P, Q and R, containing marbles in the ratio 1 : 2 : 3. Total number of marbles is 60. The above ratio can be changed to 3 : 4 : 5 by transferring:

  • 2 marbles from P to Q and 1 from R to Q

  • 3 marbles from Q to R

  • 4 marbles from R to Q

  • 5 marbles from R to P

27.Page 115

If x2 + y2 = 4xy, then x : y is ______.

  • 1 : 1

  • 1 : 2

  • 1 : 4

  • 2 : 1

28.Page 115

If 3A = 5B and 4B = 6C, then A : C is equal to ______.

  • 2 : 5

  • 3 : 5

  • 4 : 5

  • 5 : 2

29.Page 115

If A : B = 7 : 9 and B : C = 5 : 4, then A : B : C is ______.

  • 7 : 45 : 36

  • 28 : 36 : 35

  • 35 : 45 : 36

  • none of these

30.Page 115

If 8a = 9b, then the ratio of `a/9` to `b/8` is ______.

  • 1 : 1

  • 1 : 2

  • 2 : 1

  • 64 : 81

31.Page 116

If a, b, c and d are proportional, then `(a + b)/(a − b)` is equal to ______.

  • `c/d`

  • `(c - d)/(c + d)`

  • `d/c`

  • `(c + d)/(c - d)`

32.Page 116

If x : y = 3 : 2, then the ratio (2x2 + 3y2) : (3x2 – 2y2) is equal to ______.

  • 5 : 3

  • 6 : 5

  • 12 : 5

  • 30 : 19

33.Page 116

If (5a + 3b) : (2a – 3b) = 23 : 5, then the value of a : b is ______.

  • 1 : 2

  • 1 : 4

  • 2 : 1

  • 4 : 1

34.Page 116

If (4x2 – 3y2) : (2x2 + 5y2) = 12 : 19 then x : y is ______.

  • 2 : 3

  • 1 : 2

  • 2 : 1

  • 3 : 2

35.Page 116

If a : b = b : c then a4 : b4 would be equal to ______.

  • ac : b2

  • a2 : c2

  • b2 : ac

  • c2 : a2

36.Page 116

If a : b : c = 2 : 3 : 4, then `1/a : 1/b : 1/c` is equal to ______.

  • `1/4 : 1/3 : 1/2`

  • 4 : 3 : 2

  • 6 : 4 : 3

  • none of these

37.Page 116

If `1/x : 1/y : 1/z = 2 : 3 : 5`, then x : y : z is equal to ______.

  • 2 : 3 : 5

  • 5 : 3 : 2

  • 15 : 10 : 6

  • 6 : 10 : 15

38.Page 116

If (x + y) : (x – y) = 4 : 1, then (x2 + y2) : (x2 – y2) is ______.

  • 8 : 17

  • 17 : 8

  • 16 : 1

  • 25 : 9

39.Page 116

If a : b : c = 2 : 3 : 4 and 2a – 3b + 4c = 33, then the value of c is ______.

  • 6

  • 9

  • `66/7`

  • 12

40.Page 116

If x, y, z are in continued proportion, then (y2 + z2) : (x2 + y2) is equal to ______.

  • z : x

  • x : z

  • x : y

  • (y + z) : (x + y)

41.Page 116

If `a/b = b/c = c/d`, then `(b^3 + c^3 + d^3)/(a^3 + b^3 + c^3)` is equal to ______.

  • `a/b`

  • `b/c`

  • `c/d`

  • `d/a`

42.Page 116

If a : b = c : d, then `(ma + nc)/(mb + nd)` is equal to ______.

  • m : n

  • dm : cn

  • an : mb

  • a : b

43.Page 116

In an alloy, the ratio of copper and zinc is 5 : 2. If 1.250 kg of zinc is mixed in 17 kg 500 g of alloy, then the ratio of copper and zinc in the alloy will be ______.

  • 1 : 2

  • 2 : 1

  • 2 : 3

  • 3 : 2

44.Page 116

A sum of ₹6400 is divided among three workers in the ratio `3/5 : 2 : 5/3`. The share of the second worker is ______.

  • ₹2560

  • ₹3000

  • ₹3200

  • ₹3840

45.Page 116

If a sum of ₹x is divided between A and B in the ratio `a/b : c/d`, then A gets :

  • `₹ ((abx)/(ac + bd))`

  • `₹ ((abx)/(ad + bc))`

  • `₹ ((adx)/(ad + bc))`

  • `₹ ((adx)/(ab + cd))`

46.Page 117

The ratio of the number of boys and girls in a school of 720 students is 7 : 5. How many more girls should be admitted to make the ratio 1 : 1?

  • 90

  • 120

  • 220

  • 240

47.Page 117

Two numbers are in the ratio 7 : 11. If 7 is added to each of the numbers, the ratio becomes 2 : 3. The smaller number is ______.

  • 39

  • 49

  • 66

  • 77

48.Page 117

What must be subtracted from each of 7, 9, 11 and 15, so that the resulting numbers are in proportion?

  • 1

  • 2

  • 3

  • 5

49.Page 117

If p, q and r are in continued proportion, then:

  • p : q = p : r

  • q : r = p2 : q2

  • p : q2 = r : p2

  • p : r = p2 : q2

50.Page 117

The ratio of milk to water in 80 litres of a mixture is 7 : 3. The quantity of water (in litres) to be added to it to make the ratio 2 : 1, is ______.

  • 4

  • 5

  • 6

  • 8

51.Page 117

What number must be added to each of the numbers 7, 11 and 19 so that the resulting numbers may be in continued proportion?

  • –4

  • –3

  • 3

  • 4

52.Page 117

Two numbers are in the ratio of 3 : 5. If 9 is subtracted from each, they are in the ratio of 12 : 23. The larger number is ______.

  • 40

  • 45

  • 55

  • 60

53.Page 117

What number must be added to the terms of 3 : 5 to make the ratio 5 : 6?

  • 6

  • 7

  • 12

  • 13

54.Page 117

Six numbers a, b, c, d, e, f are such that ab = 1, `bc = 1/2`, cd = 6, de = 2 and `ef = 1/2`. What is the value of (ad : be : cf)?

  • 4 : 3 : 27

  • 6 : 1 : 9

  • 8 : 9 : 9

  • 72 : 1 : 9

55.Page 117

If `a = (4xy)/(x + y)`, then `((a + 2x)/(a - 2x) + (a + 2y)/(a - 2y))` equals ______.

  • 1

  • 2

  • `1/2`

  • none of these

56.Page 117

If `(sqrt(1 + x) + sqrt(1 - x))/(sqrt(1 + x) - sqrt(1 - x)) = a/b`, then x equals ______.

  • `a^2/(a + b)`

  • `b^2/(a + b)`

  • `(ab)/(a^2 + b^2)`

  • `(2ab)/(a^2 + b^2)`

57.Page 117

If `x = (sqrt(2a + 1) + sqrt(2a - 1))/(sqrt(2a + 1) - sqrt(2a - 1))`, then which of the following is true?

  • x2 + 2ax + 1 = 0

  • x2 – 2ax + 1 = 0

  • x2 + 4ax – 1 = 0

  • x2 – 4ax + 1 = 0

58.Page 117

If `a/(b + c) = b/(c + a) = c/(a + b)`, then each ratio is equal to ______.

  • `1/2`

  • –1

  • either `1/2` or –1

  • neither `1/2` nor –1

59.Page 118

If b is the mean proportion between a and c, then `(a^2 - b^2 + c^2)/(a^-2 - b^-2 + c^-2)` is equal to ______.

  • a4

  • b4

  • a2

  • b2

60.Page 118

If b is the mean proportion between a and c, then the mean proportion between (a2 + b2) and (b2 + c2) is ______.

  • a(b + c)

  • b(a + c)

  • c(a + b)

  • none of these

II. Assertion-Reason Type Questions Directions : In each question below, there are two statements labelled as Assertion (A) and Reason (R). Choose the correct answer as per the options given below:

1.Page 118

Assertion (A): If $$\frac{a}{b} = \frac{c}{d}$$, then $$\frac{a + c}{b + d} = \frac{a}{b}$$.

Reason (R): If two or more than two ratios are equal, then, each ratio = $$\frac{\text{sum of antecedents}}{\text{sum of consequents}}$$

  • Both A and R are true, and R is the correct explanation of A.

  • Both A and R are true, but R is not the correct explanation of A.

  • A is true, but R is false.

  • A is false, but R is true.

2.Page 118

Assertion (A): The mean proportion between $$a^2b$$ and $$\frac{1}{b}$$ is $$\frac{a}{b}$$.

Reason (R): The mean proportion between x and y is given by $$\sqrt{xy}$$.

  • Both A and R are true, and R is the correct explanation of A.

  • Both A and R are true, but R is not the correct explanation of A.

  • A is true, but R is false.

  • A is false, but R is true.

3.Page 118

Assertion (A): If $$2x = 3y$$ and $$4y = 5z$$, then $$x : y : z$$ is equal to $$15 : 10 : 8$$.

Reason (R): If $$x = y$$ and $$y = z$$, then we cannot find the ratio $$x : y : z$$.

  • Both A and R are true, and R is the correct explanation of A.

  • Both A and R are true, but R is not the correct explanation of A.

  • A is true, but R is false.

  • A is false, but R is true.

III. Analytical and Application Based Questions

1.Page 118

The mean proportion between two numbers is 6 and their third proportion is 48. Find the two numbers.

2.Page 118

The profit in rupees in a local restaurant and the number of customers who visited the restaurant are tabulated below for each week for one month.

Week
number
Week 1 Week 2 Week 3 Week 4
Number of
customers
1400 5600 x 3212
Profit in ₹ 28000 112000 32140 y

Find:

  1. if the number of customers and profit per week in continued proportion or not? Justify your answer.
  2. the value of x and y.

Solutions for 7: Ratio and Proportion

EXERCISE 7AEXERCISE 7BEXERCISE 7CCOMPETENCY-FOCUSED QUESTIONS
R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE chapter 7 - Ratio and Proportion - Shaalaa.com

R.S. Aggarwal solutions for Mathematics [English] Class 10 ICSE chapter 7 - Ratio and Proportion

Shaalaa.com has the CISCE Mathematics Mathematics [English] Class 10 ICSE CISCE solutions in a manner that help students grasp basic concepts better and faster. The detailed, step-by-step solutions will help you understand the concepts better and clarify any confusion. R.S. Aggarwal solutions for Mathematics Mathematics [English] Class 10 ICSE CISCE 7 (Ratio and Proportion) include all questions with answers and detailed explanations. This will clear students' doubts about questions and improve their application skills while preparing for board exams.

Further, we at Shaalaa.com provide such solutions so students can prepare for written exams. R.S. Aggarwal textbook solutions can be a core help for self-study and provide excellent self-help guidance for students.

Concepts covered in Mathematics [English] Class 10 ICSE chapter 7 Ratio and Proportion are Ratio, Proportion, Direct Applications of Ratio and Proportion, Ratio in Lowest Terms, All About Ratios: Dividing, Comparing, and Modifying Quantities, Commensurable and Incommensurable Quantities, Composition of Ratios, Concept of Continued Proportion, Properties of Proportion, Ratio, Proportion, Direct Applications of Ratio and Proportion, Ratio in Lowest Terms, All About Ratios: Dividing, Comparing, and Modifying Quantities, Commensurable and Incommensurable Quantities, Composition of Ratios, Concept of Continued Proportion, Properties of Proportion.

Using R.S. Aggarwal Mathematics [English] Class 10 ICSE solutions Ratio and Proportion exercise by students is an easy way to prepare for the exams, as they involve solutions arranged chapter-wise and also page-wise. The questions involved in R.S. Aggarwal Solutions are essential questions that can be asked in the final exam. Maximum CISCE Mathematics [English] Class 10 ICSE students prefer R.S. Aggarwal Textbook Solutions to score more in exams.

Get the free view of Chapter 7, Ratio and Proportion Mathematics [English] Class 10 ICSE additional questions for Mathematics Mathematics [English] Class 10 ICSE CISCE, and you can use Shaalaa.com to keep it handy for your exam preparation.

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