okay. so the answer seems really hard to get to, but its actually very easy. the answer is 1040. we know her bank is 3/10 full. and when she adds 520 to it. it is 4/5's full. but remember, we can break it down to 8/10, and the difference is 5/10, which is 1/2. So.. if 520 is equal to 1/2, then 2/2 is equal to 1040.