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

Example Input: Problem: if the average ( arithmetic mean ) of a and b is 45 and the average of b and c is 80 , what is the value of c − a ?
Example Output: 60

Example Input: Problem: if ( 2 ^ 16 ) ( 25 ^ s ) = 5 ( 10 ^ m ) what is the value of m ?
Example Output: 16

Example Input: Problem: a towel , when bleached , was found to have lost 20 % of its length and 10 % of its breadth . the percentage of decrease in area is
Example Output:
28 %