A group of people consists of men, women and children. Among them, 20% are men, 50% are women and the rest are children, and their average weights are 45 kg, 50 kg and 50 kg, respectively. The average weight (in kg) of the group is:​

Correct option is D

Given:

Composition: Men = 20%, Women = 50%, Children = 30% (rest)

Average weights: Men = 45 kg, Women = 50 kg, Children = 50 kg

Formula Used:

Weighted average =$$\sum (\text{proportion} \times \text{average weight})$$​​

Solution:
​$$\text{Average} = (0.20\times 45) + (0.50\times 50) + (0.30\times 50)$$​​
= 9 + 25 + 15 = 49 kg