Question

The average age of three boys is 15 years. If their ages are in the ratio 3:5:7, the age of the youngest boy is

Options

• 21 years

• 18 years

• 15 years

• 9 years

Answer 1

9 years

Explanation:

Let the age of three boys be = 3x, 5x and 7x
ATQ

`(3"x"+5"x"+7"x")/3=15`

`(15"x")/3=15,"x"=3`

youngest Boy = 3 × 3 = 9 year