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

Example Input: Problem: a number x is mistakenly divided by 10 instead of being multiplied by 10 . what is the percentage error in the result ?
Example Output: - 99 %

Example Input: Problem: gopi gives rs . 90 plus one turban as salary to his servant for one year . the servant leaves after 9 months and receives rs . 60 and the turban . find the price of the turban .
Example Output: 30

Example Input: Problem: 17 balls are numbered 1 to 17 . a ball is drawn and then another ball is drawn without replacement . what is the probability that both balls have even numbers ?
Example Output:
7 / 34