Final answer:
Stefan originally spent $113.19 to buy the bicycle and helmet. He sold them to Jin for the same amount, so his profit was $0.
Step-by-step explanation:
The question involves determining how much Stefan originally spent on a bicycle and helmet and the profit he made from selling them to Jin. Jin paid $113 for the bicycle and $0.19 for the helmet, so the total amount paid was $113.19. The statement says that Stefan sold the items at 100% of what he originally spent, meaning he sold them for exactly the price he paid.
To find how much Stefan spent originally, we simply take the total amount Jin paid, which is $113.19. Therefore, Stefan's original expense was $113.19.
To find out how much money Stefan made, we compare the selling price to the buying price. However, since the selling price is the same as the buying price, Stefan did not make any profit. Thus, his profit is $0.