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

Ex Input:
Problem: how many quarters are equal to 7 dollars ?

Ex Output:
28


Ex Input:
Problem: the ratio of the present age of viju to that of aju is 7 : 2 . 4 years from now , the ratio of the ages of viju to aju will be 5 : 2 . what was viju age 5 years ago ? ( rbi assistant 2015 )

Ex Output:
16


Ex Input:
Problem: there are 25 balls in a jar . you take out 5 blue balls without putting them back inside , and now the probability of pulling out a blue ball is 1 / 5 . how many blue balls were there in the beginning ?

Ex Output:

9 .