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.

Example Input: mrs. hilt saw a rollercoaster . 7 students rode the rollercoaster every 5 minutes . how many students rode the rollercoaster in 15 minutes ?
Example Output: 21

Example Input: a company was offering a special on cell phones for $ 2 each . but only if you spent 7 dollars a month for 4 months . how much would it end up costing you total if you bought 1 phone ?
Example Output: 30

Example Input: at the fair the 'twirly tea cups ' ride can hold 9 people per teacup . if the ride has 7 tea cups how many total people can ride at a time ?
Example Output:
63