Question

Kaixuan gave 1/4 of his money to his mother. He spent 5/18 of the remainder on a wallet and 2 t- shirtsand had $312 left. The wallet cost 4 times as much as a t-shirt. (a) How much did Kaixuan have at first? (b) How much did each t-shirt cost?

Answer 1

(m-m/4)(1-5/18)=312

[(4m-m)/4](13/18)=312

(3m/4)(13/18)=312

39m/72=312

39m=22464

m=576

So Kaixuan had $576 to start with.

....

w=4t

(3m/4)(5/18)=w+2t

15m/72=w+2t, using w=4t and m=$576 we have:

15(576)/72=4t+2t

8640/72=6t

120=6t

t=$20

So each t-shirt costs $20.