Can someone me out on this it is confusing

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?

Julie goes to the sports store and spends $40.50 before tax. she buys a pair of shorts for $21.75 and 3 pairs of socks that each cost the same amount. how much does each pair of socks cost? $$

The volume, v, of a rectangular prism is determined using the formula, where / is the length, w is the width, and his theheight of the prism. carltren solves for w and writes the equivalent equation w=using this formula, what is the width of a rectangular prism that has a volume of 138.24 cubic inches, a height of 9.6 inches,and a length of 3.2 inches?