Answer:
Originally Stefan spent $ 110, and made $ 30 selling the bike and helmet to Jin.
Step-by-step explanation:
Given that Stefan sells Jin a bicycle for $ 135 and a helmet for $ 19, and the total cost for Jin is 140% of what Stefan spent originally to buy the bike and helmet, to determine how much did Stefan spend originally and how much money did he make by selling the bicycle and helmet to Jin, the following calculation must be performed:
100 + 140 = 240
140 = 135 + 19
100 = X
(100 x (135 + 19)) / 140 = X
100 x 154/140 = X
15,400 / 140 = X
110 = X
So originally Stefan spent $ 110, and made $ 30 selling the bike and helmet to Jin.
