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

Input: Consider Input: Problem: a certain fraction is equivalent to 3 / 5 . if the numerator of the fraction is increased by 4 and the denominator is doubled , the new fraction is equivalent to 1 / 3 . what is the sum of the numerator and denominator of the original fraction ?

Output: 56

Input: Consider Input: Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively , while the third empty it in 30 hr . if all pipes are opened simultaneously , then the cistern will be filled in

Output: 6.67 hr

Input: Consider Input: Problem: if i equals the sum of the even integers from 2 to 200 , inclusive , and k equals the sum of the even integers from 20 to 200 , inclusive , what is the value of i - k ?
Output: 9