Question

The average age of $5$ members of a family is $24$ years. If the youngest member is $8$ years old, then what was the average age (in years) of the family at the time of the birth of the youngest member?

• A. $16$
• B. $20$
• C. $24$
• D. $32$

Answer 1

The correct option is B $20$

Total age of the family$=5\times 24=120$ years
Total age $8$ years ago$=120-(5\times 8)=80$ years
Number of members at the time of birth of youngest member $=4$
Required average$=\frac{80}{4}=20$