If the average age of A, B and C is 22 years and the average age of B and C is 25 years, then find A's age after 9 years.

Correct option is B

Given:

The average age of A, B, and C is 22 years.

The average age of B and C is 25 years.

Concept Used:

Average age = $$\frac{\text{Sum of ages}}{\text{Number of people}}$$​

Solution:

​$$\frac{A + B + C}{3} = 22 \implies A$$​ + B + C = 66

Average age of B and C:

​$$\frac{B + C}{2} = 25 \implies$$​ B + C = 50

Find A's age:

A + B + C - (B + C) = 66 - 50

A = 16

A's age after 9 years

16 + 9 = 25

$$\boxed{25}$$​