To solve this problem, you will need to list several multiples of 3; these are the days that the whale show will be presented. Whale show: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 Now, list several multiples of 5; these are the days that the otter show will be offered. Otter show: 5, 10, 15, 20, 25, 30 Now, compare the two to find the LCM. Whale show: 3, 6, 9, 12, 15 , 18, 21, 24, 27, 30 Otter show: 5, 10, 15 , 20, 25, 30 The whale show and otter show will occur on the same day in 15 days.