Beth has 72 marbles of three colors. Each color has the same amount of marbles. If Beth loses 5 red, twice as many blue, and three times as many yellow ones than red ones, how many marbles does she have left?
Thoughts? Step-by-step reasoning:
Beth has 72 / 3 = 24 marbles of each color. Beth has 24 - 5 = 19 red ones left. Beth lost 5 * 2 = 10 blue ones. Beth has 24 - 10 = 14 blue ones left. Beth lost 5 * 3 = 15 yellow ones. Beth has 24 - 15 = 9 yellow ones left. She has a total of 19 + 14 + 9 = 42 marbles left.
Thus, the answer is 42.