Question

The average age of a family of 6 members is 24 years. If the age of the youngest member be 6 years, then what was the average age of the family member at the birth of the youngest member (in years)?

• A. 21.6
• B. 20.5
• C. 22
• D. 22.6
• E. 21

Answer 1

The correct option is A

21.6

Total age of all members= 6 x 24 = 144 years

6 years ago, total sum of ages = 144 - (6 x 6) = 108 years

But 6 years before there were only 5 members in the family so,

Average at that time of birth of youngest member = $\frac{108}{5}=21.6$ yrs.