Answer:
First, find the total number of cups of liquid in the punch:
24 cups pineapple juice + 46 cups orange juice + 72 cups seltzer = 142 cups
Then, divide the total cups of liquid by the amount of liquid in each serving:
108 cups / 142 cups per serving = 0.76 servings
Therefore, approximately 0.76 servings can be made from 108 cups of punch.