What would the total bill be of a painting that costs $20.50 with a tax rate of 6%?

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 someone me and plz do the problem

What are the exclude value of mn+3m