The task is to generate the correct answer for a given math problem.

Example Input: Problem: a car traveled 560 miles per tankful of gasoline on the highway and 336 miles per tankful of gasoline in the city . if the car traveled 6 fewer miles per gallon in the city than on the highway , how many miles per gallon did the car travel in the city ?
Example Output: 9

Example Input: Problem: the profits of qrs company rose 30 % from march to april , then dropped 20 % from april to may , then rose 50 % from may to june . what was the percent increase for the whole quarter , from march to june ?
Example Output: 56 %

Example Input: Problem: the length of the bridge , which a train 500 metres long and travelling at 42 km / hr can cross in 60 seconds , is ?
Example Output:
200 m