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

[Q]: Gwen had 18 math problems and 11 science problems for homework . If she finished 24 of the problems at school , how many problems did she have to do for homework ?
[A]: 5


[Q]: Roger was putting his spare change into piles . He had 3 piles of quarters and 3 piles of dimes . If each pile had 7 coins in it , how many coins did he have total ?
[A]: 42


[Q]: Debby 's class is going on a field trip to the zoo . If each van can hold 9 people and there are 40 students and 14 adults going , how many vans will they need ?
[A]:
6