### In an examination average marks obtained by the girls of a class is 85 and the average marks obtained by the boys of the same class is 87. If the girls and boys are in the ratio 4 : 5, average marks of the whole class (approx.) is closest to :

A. 86.5 B. 85.9 C. 86.4 D. 86.1 Answer: Option D

### Solution(By Apex Team)

$\begin{array}{l}\text{ Average of whole class }\\ =\Large\frac{85\times4+87\times5}{5+4}\\ =\Large\frac{340+435}{9}\\ =\Large\frac{775}{9}\\ =86.1\end{array}$

A. 20
B. 21
C. 28
D. 32

A. 18
B. 20
C. 24
D. 30

A. 10 years
B. 10.5 years
C. 11 years
D. 12 years