The sum of ages of 5 children born at the intervals of 3 years each is 50 years. What is the age of the youngest child?

Question

A man had nine children, all born at regular intervals, and the sum of the squares of their ages was equal to the square of his own. What was the age of each? Every age was an exact number of years.

Answer 1

Age os Yougest child is 4 yrs

let x = age of yougest child
so,
x+3, x+6, x+9 & x+12 are ages of rest 4 childs

thus x+x+3+x+6+x+9+x+12 = 50
5x + 30 = 50
thus
x = 4