Question

The average of the first 3 children in a class is 13.5 years. if the sum of the ages of the first two children is 25 years, then what is the age of the third child?

Answer 1

let the ages of the children be x1,x2,x3,. then;

x1+x2+x3/3 = 13.5
x1+x2+x3 = 40.5

x1+x2 = 25

25+x3 = 40.5
x3 = 15.5

hence the age of third child is 15.5 years
that is 15years and six months.

hope this helped you ..........!

Answer 2

(25+x)÷3 =13.5
25+x=40.5
x=40.5-25
x=15.5 years
x=15 years 6 months