Question

Two numbers are in ratio 7 ∶ 5. If 1 is subtracted from the first number and 3 is subtracted from the second number, their ratio becomes 3 ∶ 2. What is the second number?

1. 25
2. 35
3. 45
4. 55

Answer 1

Correct Answer - Option 2 : 35

Given:

The ratio of two numbers = 7 ∶ 5

Calculation:

Let first number = 7X

Second number = 5X

If 1 is subtracted from first number and 3 is subtracted from second number, then ratio = (7X – 1)/(5X - 3)

⇒ (7X – 1)/(5X - 3) = 3/2

⇒ 3(5X - 3) = 2(7X - 1)

⇒ 15X – 9 = 14X – 2

⇒ 15X – 14X = 9 – 2

⇒ X = 7

First number = 7X

= 7 × 7 = 49

Second number = 5X

= 5 × 7 = 35

∴ Second number is 35