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

Ex Input:
Problem: a train running at the speed of 72 km / hr crosses a pole in 9 seconds . find the length of the train .

Ex Output:
180 meter

Ex Input:
Problem: you enter a weight loss challenge game and manage to lose 12 % of your body weight . for the final weigh in you are forced to wear clothes that add 2 % to your weight . what percentage of weight loss is measured at the final weigh in ?

Ex Output:
10.24 %

Ex Input:
Problem: a student travels from his house to school at 12 km / hr and reaches school 2 hours late . the next day he travels 20 km / hr and reaches school 1 hour early . what is the distance between his house and the school ?

Ex Output:
90