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

Example Input: Problem: a rectangular plot measuring 90 metres by 50 metres is to be enclosed by wire fencing . if the poles of the fence are kept 10 metres apart , how many poles will be needed ?
Example Output: 28

Example Input: Problem: a number x is 5 times another number y . the percentage that y is less than x is
Example Output: 80 %

Example Input: Problem: a house wife saved $ 2.50 in buying an item on sale . if she spent $ 25 for the item , approximately how much percent she saved in the transaction ?
Example Output:
9 %