The sum of ages of 5 children born at the intervals of 3 years each is 80 years. What is the age of the youngest child? Pick.
A) 3 years  B) 4 years  C) 6 years  D) 7 years  E) 10 years
Let the ages of children be x, (x + 3), (x + 6), (x + 9) and (x + 12) years.   Then, x + (x + 3) + (x + 6) + (x + 9) + (x + 12) = 80   5x = 50   x = 10.   Age of the youngest child = x = 10 years.   10 years)
<result>E</result>
The sum of ages of 5 children born at the intervals of 3 years each is 80 years. What is the age of the youngest child?