Question

The average age of 7 people in a family is 24 years, If the age of the youngest member of the family is 3 years, what was the average age of the family at the birth of the youngest member? 
1. 24 years
2. 24.5 years
3. 25 years
4. 25.5 years
5. 27.5 years

Answer 1

Correct Answer - Option 2 : 24.5 years

Given:

Average age of 7 people = 24 years

Age of youngest member = 3 years

Formula used:

Average = sum of observations/total number of observations

Calculation:

Total age of 7 members = 24 × 7 = 168 years

Total age 3 years ago = 168 - (7 × 3) = 147 years

The number of members at that time was 6

So, average age = 147/6 = 24.5 years

∴ The average age was 24.5 years