Algebra (inequality)

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 marbles or more, the class has a party. Right now, the jar contains 24 marbles. Let r represent the number of additional times the class is rewarded. Write an inequality to determine how many more times the class needs to be rewarded in order to earn a party.