working backwards to solve a word problem

Question

a person is given some amount of cash for their birthday. they spend 1/4 of their money on dinner out. They spend 3/5 of what remains on school supplies. Next they spend $8 of the remaining money on a very bad haircut. Finally they spend 1/2 of what they have left on a video game. They have $20 remaining. How much money did they start with?

Answer 1

$70-$18.75 (25%) = $51.25

 

$51.25 - $3.07 (6%) = $48.18

 

$48.18 - $8= $40.18

 

$40.18 - 20.18 (50%)= $20.00