There is only one answer out of those three PLEASE HELP ME I'M FALLING IN MATH CLASS, PLEASE HELP ME! (no link's please)

Mrs. morton has a special reward system for her class. when all her students behave well, she rewards them by putting 3 marbles into a marble jar. when the jar has 100 or more marbles, the students have a party. right now, the the jar has 24 marbles. how could mrs. morton reward the class in order for the students to have a party?

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?