When solving this problem we need to remember that it is asking us to find how much money she gained throughout the day, NOT the total amount she had at the end of the day. To find how much money she gained, simply subtract one hundred by nine hundred.
900 - 100
800
Therefore, $800 was the change in how much money she had.
No more than 74 on average of 5 games means no more than 370 shots on total. If you add all of the numbers up you will get 292, so he can still shoot 370-292=78 in the last round, which is answer choice B.
