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

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

A: a ) 7
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Q: 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 ?

A: 50 %
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Q: Problem: the average of first 9 natural numbers is ?

A:
4.5
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