You are given a math word problem and you are supposed to apply multiple mathematical operators like addition, subtraction, multiplication or division on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

In a video game , each enemy defeated gives you 5 points . If a level has 8 enemies total and you destroy all but 6 of them , how many points would you earn ?
10

At a sale , the cost of a pair of shoes was reduced from 42 dollars to 33.6 dollars . What was the percent of discount ?
20

Joan joined her school 's band . She bought a trumpet for $ 149.16 , a music tool for $ 9.98 , and a song book which was $ 4.14 . Joan found $ 8.65 in her pocket . How much did Joan spend at the music store ?

163.28