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

Ex Input:
Problem: the ratio between the sale price and the cost price of an article is 12 : 7 . what is the ratio between the profit and the cost price of that article ?

Ex Output:
5 : 7

Ex Input:
Problem: if a - b = 6 and a 2 + b 2 = 50 , find the value of ab .

Ex Output:
a ) 7

Ex Input:
Problem: how many integers between 324,700 and 458,600 have tens digit 1 and units digit 3 ?

Ex Output:
1,33