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

Example Input: Problem: if a - b = 5 and a 2 + b 2 = 31 , find the value of ab .
Example Output: 3

Example Input: Problem: when the price of a product was decreased by 20 % , the number sold increased by 60 % . what was the effect on the total revenue ?
Example Output: 28 %

Example Input: Problem: an engineer designed a ball so that when it was dropped , it rose with each bounce exactly one - half as high as it had fallen . the engineer dropped the ball from a 16 - meter platform and caught it after it had traveled 45 meters . how many times did the ball bounce ?
Example Output:
4