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

Input: Consider Input: Problem: a lent rs . 5000 to b for 2 years and rs . 3000 to c for 4 years on simple interest at the same rate of interest and received rs . 1540 in all from both of them as interest . the rate of interest per annum is ?

Output: 7 %


Input: Consider Input: Problem: a rectangle having length 89 cm and width 34 cm . if the length of the rectangle is increased by eighty percent then how much percent the breadth should be decreased so as to maintain the same area .

Output: 47.33 %


Input: Consider Input: Problem: 6,61 , 212,507 , _ ?


Output: 994