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

Example Input: Problem: the owner of a furniture shop charges his customer 25 % more than the cost price . if a customer paid rs . 1000 for a computer table , then what was the cost price of the computer table ?
Example Output: 80

Example Input: Problem: what decimal fraction is 90 ml of a litre ?
Example Output: . 09

Example Input: Problem: on my sister ' s birthday , she was 126 cm in height , having grown 5 % since the year before . how tall was she the previous year ?
Example Output:
120 cm