Since the children were born at the interval of three years, let us assume their ages as x, x+3,x+6,x+9, and x+12. given- the sum of five children is 50 therefore, x+x+3+x+6+x+9+x+12 = 50 5x+30 = 50 5x = 50-30 5x=20 x=4 Hence, the age of the youngest child is 4 years.