The oldest child in a family of four children is twice as old as the youngest. The two middle children are 12 and 15 years old. If the average age of the children is 13.5, how old is the youngest child?

Question

The oldest child in a family of four children is twice as old as the youngest. The two middle children are 12 and 15 years old. If the average age of the children is  13.5, how old is the youngest child?

Reiny · Answer

youngest ---- x oldest ---- 2x (2x + 12 + 15 + x)/4 = 13.5 3x + 27 = 54 take over

Anonymous · Answer

x=9