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

Example Input: Problem: if a - b = 6 and a 2 + b 2 = 50 , find the value of ab .
Example Output: a ) 7

Example Input: Problem: the smallest value of n , for which n + 2 is not a prime number , is
Example Output: 2,4

Example Input: Problem: in a lottery there are 20 prizes and 35 blanks . a lottery is drawn at random . what is the probability of getting a prize
Example Output:
4 / 11