You buy 20 shares of a stock at 31 1/2 and sell at 35 1/4 do you gain or loose how much​

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Isuck at math ; ^; m a student solved this problem and said the answer is 3 feet. chase had a roll of ribbon that contained 7 7/8  feet of ribbon. he cut off one piece that was 3 5/8  feet long and another piece that was 1 1/4  feet from the roll. how much ribbon was left on the roll? is the student's answer reasonable? yes, the answer is reasonable. no, the answer is not reasonable. it should be about 2 feet. no, the answer is not reasonable. it should be about 13 feet. no, the answer is not reasonable. it should be about 4 feet.

Write the expression in complete factored form. 5n_(c - 3) - n(c - 3) =