The sum of the ages of 5 children born at interval of 2 years each is 40 years. What is the age of the eldest child?

Correct option is D

Solution:

Let the ages of the children be x, (x + 2), (x + 4), (x + 6), and (x + 8).

According to question,

x + (x + 2) + (x + 4) + (x + 6) + (x + 8) = 40

=> 5x + 20 = 40

=> 5x =  40 -20 = 20

=> x = 4

∴ Age of the eldest child = x + 8 = 4+8 = 12 years