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

Example Input: Problem: an aeroplane covers a certain distance of 670 kmph in 6 hours . to cover the same distance in 6 1 / 4 hours , it must travel at a speed of
Example Output: 643

Example Input: Problem: find the area of trapezium whose parallel sides are 20 cm and 18 cm long , and the distance between them is 20 cm ?
Example Output: 380 cm 2

Example Input: Problem: a train running at a speed of 36 kmph crosses an electric pole in 12 seconds . in how much time will it cross a 350 m long platform ?
Example Output:
47 sec