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

Example Input: Problem: the curved surface of a sphere is 64 cm 2 . find its radius ?
Example Output: 4', 'd ) 9', 'e ) 7'

Example Input: Problem: a salt manufacturing company produced a total of 2000 tonnes of salt in january of a particular year . starting from february its production increased by 100 tonnes every month over the previous months until the end of the year . find its ave 66 rage daily production for that year ?
Example Output: 83

Example Input: Problem: vehicle x is 22 miles ahead of vehicle y , which is traveling the same direction along the same route as vehicle x . if vehicle x is traveling at an average speed of 36 miles per hour and vehicle y is traveling at an average speed of 45 miles per hour , how long will it take vehicle y to overtake and drive 23 miles ahead of vehicle x ?
Example Output:
5 hours