In a class there are 32 boys and 28 girls. The average age of the boys in the class is 14 years and the average age of the girls in the class 13 years. What is the average age of the whole class (rounded to two digits after decimal) ?

A. 12.51

B. 13.42

C. 13.50

D. 13.53

E. None of these

Answer: Option D

Solution(By Examveda Team)

Required average
$$\eqalign{ & = \left( {\frac{{32 \times 14 + 28 \times 13}}{{32 + 28}}} \right) \cr & = \left( {\frac{{448 + 364}}{{60}}} \right) \cr & = \left( {\frac{{812}}{{60}}} \right) \cr & = 13.53 \cr} $$