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

Ex Input:
Problem: each of the products produced yesterday was checked by worker x or worker y . 0.5 % of the products checked by worker x are defective and 0.8 % of the products checked by worker y are defective . if the total defective rate of all the products checked by worker x and worker y is 0.74 % , what fraction of the products was checked by worker y ?

Ex Output:
4 / 


Ex Input:
Problem: how many prime numbers are between 51 / 13 and 89 / 9 ?

Ex Output:
2


Ex Input:
Problem: an aeroplane covers a certain distance at a speed of 150 kmph in 2 hours . to cover the same distance in 1 2 / 3 hours , it must travel at a speed of :

Ex Output:

180 kmph