Jinfa, upon receiving his paycheck, spent four-fifths of it on car repairs and then bought a $40 gift for his mother. He had $64 left. How much was his paycheck?
you’ll do it in reverse here so $64 + $40 = $104 if he spent 4/5 on car repairs then had a remaining $104, the 1/5 is equal to $104. multiply $104 by 5 and it gives you $520