Question

A group of people contains men, women and children. If 40% of them are men, 35% are women and rest are children, and their average weights are 70 kg, 60 kg and 30 kg, respectively. The average weight of the group is:

• A. 45.5 kg
• B. 56.5 gm
• C. 45.5 gm
• D. 56.5 kg

Answer 1

Answer:

D. 56.5 kg

The average weight of the group is 56.5 kg.

## 1. Find the percentage of children

The total percentage of the group must equal 100%.

$\text{Children \%} = 100\% - (40\% + 35\%) = 25\%$

## 2. Calculate the weighted total weight

Assume there are 100 people in total to make the calculation straightforward:

* Men (40 people): $40 \times 70 \text{ kg} = 2,800 \text{ kg}$

* Women (35 people): $35 \times 60 \text{ kg} = 2,100 \text{ kg}$

* Children (25 people): $25 \times 30 \text{ kg} = 750 \text{ kg}$

$\text{Total weight} = 2,800 + 2,100 + 750 = 5,650 \text{ kg}$

## 3. Find the average weight

Divide the total weight by the total number of people (100).

$\text{Average weight} = \frac{5,650 \text{ kg}}{100} = 56.5 \text{ kg}$