Question

The ratio between two numbers is 3 : 7. The largest number is greater than smallest number by 20. Find the smaller number. 
1. 21
2. 12
3. 20
4. 15

Answer 1

Correct Answer - Option 4 : 15

Given:

The ratio between two numbers is 3 : 7.

Largest number is greater than smallest number by 20

Calculation:

Let the two number be A and B, where A = 3x and B = 7x

Given, largest number is greater than smallest number by 20

⇒ 7x – 3x = 4x = 20

⇒ x = 5

∴ Smaller number = 3x = 3 × 5 = 15