### In a pre school, the average weight of 30 girls in a class among 50 students is 16 kg and that of the remaining students is 15.5 kg. What is the average weight of all the students in the class ?

A. 15.2 kg B. 15.8 kg C. 15.4 kg D. 15.6 kg Answer: Option B

### Solution(By Apex Team)

$\begin{array}{l}\text{According to the question,}\\ \text{Average},\\ =\Large\frac{30 \times 16+20 \times 15.5}{50}\\ =\Large\frac{480+310}{50} \\ =\Large\frac{790}{50} \\ =15.8 \mathrm{~kg} \end{array}$

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