20% as a decimal is 0.20. So, 240 x 0.20 is 48 tuna sandwiches, 40% as a decimal is 0.40 so 240 x 0.40 is 96 ham sandwiches. 48 + 96 is 144. So that means that the remaining 96 sandwiches are Egg Salad Sandwiches.
8 gallons= 128 cups 20 guests x 2 cups each= 40 cups will be gone 128-40= 88 cups left over 88 cups= 5.5 gallons of punch left at the end of the party.
