A family consists of two grandparents, two parents and four grandchildren. The average age of the grandparents is 67 years, that of the parents is 35 years and that of the grandchildren is 9 years. What is the average age of the family?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 30 years.
Average = Sum of observations/Number of observations
Sum of the ages of all the family member = 67 × 2 + 35 × 2 + 4 × 9
⇒ 134 + 70 + 36 = 240
Total family members = 8
Required average = 240/8 = 30 years