by Sana

(Islamabad,Pakistan.)

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?

Let x be the age of the youngest child.

Let x + 3 be the age of the second child.

Let x + 6 be the age of the third child.

Let x + 9 be the age of the fourth child.

Let x + 12 be the age of the fifth child.

The sum of their ages is equal to 50 as shown below

x + x + 3 + x + 6 + x + 9 + x + 12 = 50

x + x + x + x + x + 3 + 6 + 9 + 12 = 50

5x + 30 = 50

Subtract 30 from both sides

5x + 30 - 30 = 50 - 30

5x = 20

Divide both sides by 5

5x/5 = 20/5

x = 4

The age of the youngest child is 4.