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

Ex Input:
Problem: a and b can do a piece of work in 7 days . with the help of c they finish the work in 5 days . c alone can do that piece of work in ?

Ex Output:
30 days


Ex Input:
Problem: a snooker tournament charges $ 45.00 for vip seats and $ 20.00 for general admission ( “ regular ” seats ) . on a certain night , a total of 320 tickets were sold , for a total cost of $ 7500 . how many fewer tickets were sold that night for vip seats than for general admission seats ?

Ex Output:
276


Ex Input:
Problem: the price of stock decreased by 5 % last year and rose by 10 % this year . what is the net percentage change in the price of the stock ?

Ex Output:

4.5