The sum of the ages of 6 children born at the interval of two years each is 90 years. What is the age (in years) of the eldest child?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 20.
The sum of the ages of 6 children born at an interval of 2 years each, is 90.
Let the present age of the youngest child be Q.
Hence, the ages of other children in ascending order are (Q + 2), (Q + 4), (Q + 6), (Q + 8), (Q + 10)
So, Q + (Q + 2) + (Q + 4) + (Q + 6) + (Q + 8) + (Q + 10) = 90
⇒ 6Q + 30 = 90
⇒ Q = 60/6 = 10
⇒ Q + 10 = 10 + 10 = 20
∴ The age of the eldest child is 20 years.