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

Example Input: Problem: the sum of all the digits of the integers from 18 to 21 inclusive is 24 ( 1 + 8 + 1 + 9 + 2 + 0 + 2 + 1 = 24 ) . what is the sum t of all the digits of the integers from 0 to 99 inclusive ?
Example Output: 900

Example Input: Problem: i had rs . 10000 with me . out of this , money i lent some money to a for 2 years at 15 % simple interest . i lent the remaining money to b for an equal number of years at 18 % simple interest . after 2 years , i found that a had given me rs . 360 more as interest as compared to ( b ) the amount of money which i had lent to b must have been
Example Output: 4000

Example Input: Problem: an article is bought for rs . 675 and sold for rs . 775 , find the gain percent ?
Example Output:
14.8 %