instruction:
You are given a math word problem and you are supposed to apply multiplication or division mathematical operators on the numbers embedded in the text to answer the following question and then only report the final numerical answer.
question:
Mark 's father gave him $ 85 . Mark bought 10 books , each of which cost $ 5 . How much money does Mark have left ?
answer:
35


question:
At the fair Adam bought 13 tickets . After riding the ferris wheel he had 4 tickets left . If each ticket cost 9 dollars , how much money did Adam spend riding the ferris wheel ?
answer:
81


question:
Marcia spent 300 minutes working on her science project . How many hours did Marcia spend on her science project ?
answer:

5