The sum of ages of 5 children born at the intervals of 3 years each is 50 years. Find out the age of the youngest child?  Select:
A) 9  B) 8  C) 7  D) 6  E) 4

Rationale: let the age of the youngest child = x then , the ages of 5 children can be written as x , ( x + 3 ) , ( x + 6 ) , ( x + 9 ) and ( x + 12 ) x + ( x + 3 ) + ( x + 6 ) + ( x + 9 ) + ( x + 12 ) = 50 ⇒ 5 x + 30 = 50 ⇒ 5 x = 20 ⇒ x = 205 = 4 answer is e .
Answer: E