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

Example Input: Problem: a cycle is bought for rs . 900 and sold for rs . 1080 , find the gain percent ?
Example Output: 20 %

Example Input: Problem: the cross - section of a cannel is a trapezium in shape . if the cannel is 8 m wide at the top and 6 m wide at the bottom and the area of cross - section is 700 sq m , the depth of cannel is ?
Example Output: 100

Example Input: Problem: a library has an average of 510 visitors on sundays and 240 on other day . the average number of visitors in a month of 50 days starting with sunday is
Example Output:
171