Answer:
His gain is 3.50$ which is also 50% of 7
Explanation:
for next time so you dont gotta waste points all you have to do is go 10.50 -7.00 =3.50 and then just ask go ogle if you are able what percentage is 3.50 of 7.00 because 7.00$ is what he had to pay for so he is making a 50% gain