Question

A family consists of two parents and three children. If the average age of the parents is 36 years and that of the children is 10 years. Find the average age (in years) of the family.
1. 20
2. 20.4
3. 20.8
4. 21

Answer 1

Correct Answer - Option 2 : 20.4

Given:

Average age of two parents = 36 years

Average age of three children = 10 years

Formula Used:

Average age of a family = Sum of the ages of all the members/ Total number of members in the family

Calculation:

Sum of the ages of all the members in the family = (36 × 2) + (10 × 3) = 72 + 30 = 102

Number of members in the family = 3 + 2 = 5

∴ Average age of the family = 102/5 = 20.4 years