Who is stronger me 2 or my brother 1

The verbal translation for the difference of m and 7 increased by 15

Can someone answer this question? : )

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?