You are given a math word problem and you are supposed to apply a single mathematical operator 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]: the roller coaster at the state fair costs 6 tickets per ride . if 8 friends were going to ride the roller coaster how many tickets would they need ?
[EX A]: 48

[EX Q]: a store has 49 shirts . after selling some there were 28 left . how many did they sell ?
[EX A]: 21

[EX Q]: she also tried to get to know the teachers in the school . she found out that there are 7 departments in the school and each department has 20 teachers . how many teachers are there in total ?
[EX A]:
140