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

Example Input: Problem: a merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent of the cost would the gross profit on the item have been if it had been sold without the discount ?
Example Output: 50 %

Example Input: Problem: what is the diagonal of a square field whose perimeter is 64 m ?
Example Output: 16 √ 2 m

Example Input: Problem: last year a worker saved 4 % of her annual salary . this year , she made 10 % more money than last year and she saved 5 % of her salary . the amount she saved this year was what percent of the amount she saved last year ?
Example Output:
137.5 %