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: two cars start at the same time from opposite ends of a highway that is 175 miles long . one car is riding at 25 mph and the second car is riding at 45 mph . how long after they begin will they meet ?

Ex Output:
2.5

Ex Input:
Problem: 9 years ago i was 5 times as old as my eldest son . today i am 3 times his age . how old am i now ?

Ex Output:
54