4.65 0.72 0.12 in dollars instead of cents

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?

Can anyone me with this question?

What is the distance between (5 - 2i) and (8 + i)?