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

Example Input: Problem: if a drawing has an outer circle of diameter 30 and an inner circle of diameter 24 , then what fraction of outer circle ' s surface is not covered by the inner circle ?
Example Output: 9 / 25', 'e ) 2 / 3'

Example Input: Problem: of the seven - digit positive integers that have no digits equal to zero , how many have two digits that are equal to each other and the remaining digit different from the other two ?
Example Output: 152409600

Example Input: Problem: what is the sum of the multiples of 4 between 63 and 151 inclusive ?
Example Output:
233