Question

The average age of a family of 5 members is 30 years. If the age of the youngest member is 10 years, what was the average age of the family just a day before the birth of the youngest member?

• A. 20
• B. 25
• C. 28
• D. 35

Answer 1

The correct option is B 25

Sum of ages of family members except the youngest member $=(5\times 30)-10=140$
Sum of ages of the members before the youngest member was born $=140-(4\times 10)=100$
Their average age $=\frac{100}{4}=25$ years