TASK DEFINITION: The task is to generate the correct answer for a given math problem.
PROBLEM: Problem: if the cost price of 50 articles is equal to the selling price of 40 articles , then the gain or loss percent is ?

SOLUTION: 25 %

PROBLEM: Problem: a van takes 5 hours to cover a distance of 495 km . what speed in kph should the van maintain to cover the same distance in 3 / 2 of the previous time ?

SOLUTION: 66

PROBLEM: Problem: the ratio between the presents of the a and b is 2 : 3 . if b is 5 years older than a , what will be the ratio of the ages of a and b after 5 years ?

SOLUTION:
3 : 4