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: a diagonal of a polygon is an segment between two non - adjacent vertices of the polygon . how many diagonals does a regular 20 - sided polygon have ?
Example Output: 170', 'c ) 1425', 'd ) 2025', 'e ) 2500'

Example Input: Problem: if ( 5 ^ 9 ) ( 9 ^ 5 ) = 3 ( 15 ^ x ) , what is the value of x ?
Example Output:
9