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

[EX Q]: Zach scored 42 points in the football game . Ben scored 21 points . How many more points did Zach score ?
[EX A]: 21

[EX Q]: Kenneth has 3 marbles . He buys 6 more . Later , Kenneth buys 15 apples at the store . How many marbles does Kenneth have in all ?
[EX A]: 9

[EX Q]: Scott has 4 tickets . Ernest has with 9 tickets . Ernest finds another 72 . How many tickets does Ernest end with ?
[EX A]:
81