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]: At lunch a waiter had 7 customers and 5 of them did n't leave a tip . If he got $ 3 each from the ones who did tip , how much money did he earn ?
[EX A]: 6

[EX Q]: A store had 5 oranges in a bin . If they threw away 2 of the old ones and put 28 new ones in the bin how many would be in the bin ?
[EX A]: 31

[EX Q]: Paul made 68 dollars mowing lawns and 13 dollars weed eating . If he only spent 9 dollar a week , how long would the money last him ?
[EX A]:
9