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.

[EX Q]: A worksheet had 7 problems on it . If a teacher had 17 worksheets to grade and had already graded 8 of them , how many more problems does she have to grade ?
[EX A]: 63

[EX Q]: An MP3 player costs 40 dollars . The sales tax is 2.4 dollars . What is the percent of sales tax ?
[EX A]: 6

[EX Q]: Each chocolate bar in a box cost $ 4 . If a box had 11 bars total and Vanessa sold all but 7 bars , how much money would she have made ?
[EX A]:
16