upon receiving his paycheck, he spent two-thirds of it on car repairs and then bought a $40 gift for his mother. He had $64 left. How much was the paycheck?

Question

this is solved using a strip diagram 

Answer 1

If he already spent 2/3, what is left before he bought gift was 1/3, therefore

 

$40+64 is equal to 1/3 of amount=$104

 

1/3+2/3=3/3 or 1( whole amount)

 

If 1/3=$104, then 3/3=3*$104=$312

 

original amount was $312