The average age of 20 boys in a class is 12 years. 5 new boys are admitted to the class whose average age is 7 years. The average age of all the boys in the class becomes:

A. 8.2 years

B. 9.5 years

C. 12.5 years

D. 11 years

Answer: Option D

Solution(By Examveda Team)

According to the question,
Average
= $$\frac{20 × 12 + 5 × 7}{25}$$
= $$\frac{240 + 35}{25}$$
= $$\frac{275}{25}$$
= 11 years