Answer:
Stefan originally spent $ 110 on the bike and helmet, with which he is making a profit of $ 33.
Step-by-step explanation:
Since Stefan sells Jin a bicycle for $ 125 and a helmet for $ 18, and the total cost for Jin is 130% 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 calculations must be performed:
130 = 125 + 18
100 = X
100 x (125 + 18) / 130 = X
100 x 143/130 = X
14,300 / 130 = X
110 = X
143 - 110 = 33
Therefore, Stefan originally spent $ 110 on the bike and helmet, with which he is making a profit of $ 33.
