Ratio Questions and Answers - Practice Problems & Solutions

Q21 :

If the ratio of two numbers is 1:5 and their product is 320, then the difference between the squares of these two numbers is :

A

1024

B

1256

C

1536

D

1435

View Answer

Correct Answer: C

1536

Description:

Let ratio be $x$

then 1st no. be $x$

2nd no. be $5x$

$therefore x times 5x = 320$

$therefore x = 8$

Numbers are 8, 40

$therefore text{ Difference } = 40^2 - 8^2 = 1536$

Q22 :

The total rice product is 64 million tons in island A and 256 million tons in island B. To present this information in the form of circle diagrams, the ratio of the radii of circles is:

A

1 : 4

B

1 : 3

C

1 : 3.5

D

1 : 2

View Answer

Correct Answer: D

1 : 2

Description:

$text{Here, } pi r^2 = 64, pi r_2 : ^2 = 256$

$therefore dfrac{pi r_1 :^2}{pi r_2 :^2} = dfrac{64}{256}$

$therefore r_1 : r_2 = 1 : 2$

Q23 :

The annual incomes of two persons are in the ration 9 : 7 and their expenses are in the ratio 4 : 3. If each of them saves Rs. 2,000 per year, then their annual incomes are :

A

Rs. 18,000 and Rs. 14,000

B

Rs. 27,000 and Rs. 21,000

C

Rs. 36,000 and Rs. 28,000

D

Rs. 45,000 and Rs. 35,000

View Answer

Correct Answer: A

Rs. 18,000 and Rs. 14,000

Description:

Let the ratio be $x$ then, by question

$begin{aligned} frac{9x - 2000}{7x -2000} &= frac{4}{3} Rightarrow 4 (7x - 2000) &= 3 (9x - 2000) Rightarrow x &= 2000 end{aligned}$

$therefore$ Annual incomes are Rs. $9x$ i.e. Rs. 18000 and Rs $7x$ i.e. Rs. 14000