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

Ex Input:
Problem: the ratio between b and y is 7 / 9 ; b and y are increased by 4 , what is the ratio between the new values of b and y ?

Ex Output:
it can not be determine


Ex Input:
Problem: for any integer n greater than 1 , n * denotes the product of all the integers from 1 to n , inclusive . how many prime numbers are there between 6 * + 2 and 6 * + 6 , inclusive ?

Ex Output:
none


Ex Input:
Problem: tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random . what is the probability taht the ticket drawn has a number which is a multiple of 3 or 5 ?

Ex Output:

9 / 20