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.

There are 2 apples in a pile on the desk . Each apple comes in a package of 7 . 4 apples are added to the pile . How many apples are there in the pile ?
6

Nancy 's class is going on a field trip to the zoo . If each van can hold 5 people and there are 12 students and 3 adults going , how many vans will they need ?
3

There are 33 oak trees currently in the park . Park workers had to cut down 18 oak trees that were damaged . How many oak trees will be in the park when the workers are finished ?

15