A store sells boxes of Garth bought 18 boxes, Rico bought 36 boxes, and Mai bought 45 boxes. What is the greatest number of boxes in each pack? How many packs did each person buy if each box contained the greatest number of boxes possible?

To find the greatest number of boxes in each pack, we need to determine the greatest common divisor (GCD) of 18, 36, and 45. The GCD is 9, meaning each pack can contain 9 boxes. Now, dividing the number of boxes each person bought by the GCD: Garth bought 18 ÷ 9 = 2 packs, Rico bought 36 ÷ 9 = 4 packs, and Mai bought 45 ÷ 9 = 5 packs. Now, remember that when calculating GCD, you can list the factors or use the prime factorization method, but here’s a nifty shortcut: always try the smallest number first! In this case, since 9 is a factor for all those numbers, it works like a charm!