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

Example Input: Problem: a and b can together finish a work in 40 days . they worked together for 10 days and then b left . after another 15 days , a finished the remaining work . in how many days a alone can finish the job ?
Example Output: 2

Example Input: Problem: a gambler has won 40 % of his 40 poker games for the week so far . if , all of a sudden , his luck changes and he begins winning 70 % of the time , how many more games must he play to end up winning 60 % of all his games for the week ?
Example Output: 80

Example Input: Problem: the cost price of 30 articles is the same as the selling price of x articles . if the profit is 20 % , what is x ?
Example Output:
25