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]: when they arrived at happyland they immediately went in and bought their tickets . if each ticket cost $ 17 and they bought 8 tickets how much did they spend on tickets ?
[EX A]: 136

[EX Q]: mrs. hilt bought 6 hot dogs . each hot dog cost 50 cents . how much money did she pay for all of the hot dogs ?
[EX A]: 300

[EX Q]: the kids from oakwood elementary school are visiting a bird zoo for their field trip . to get to the bird zoo from the school the kids have to ride some buses . if there are 7 buses and each bus has 3 adult supervisors to guide the children how many supervisors are there in total ?
[EX A]:
21