Question

Joe earned money for baby-sitting , he spent 1/4 of the money on a guitar then he gave 1/4 to charity , if he has $108 left how much money did he start with?

Answer 1

216 US dollars

Explanation:

Let the amount he earned for babysitting be x

He spent 1/4 of x on guitar=(1/4)×x=1/4x

He gave 1/4 of x to charity= (1/4)×x=1/4x

Equation 1

Total amount left=(Total amount earned -Total amount spent)

Total amount earned=x

Total amount spent=(Spent on Guitar+Spent on Charity)=(1/4x)+(1/4x)=1/2x=0.5x

Total amount left=108 US dollars

Substituting in equation 1

108=(x-0,5x)

Solving

0.5x/0.5=108/0.5

x=216 US dollars

He started with 216 US dollars