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

Problem: if a a b = 2 a - 3 b + ab , then 3 a 2 + 2 a 3 is equal to :
7

Problem: a merchant sells an item at a 20 % discount , but still makes a gross profit of 20 percent of the cost . what percent of the cost would the gross profit on the item have been if it had been sold without the discount ?
50 %

Problem: a number x is 5 times another number y . the percentage that y is less than x is
80 %