Roberto wants to display his 18 sports cards in an album. Some pages hold 2 cards and others hold 3 cards. How many different ways can Robert display his figures?

3 is an odd number, so we need an even number of sets of 3 cards because 18 is an even number.

So we need 0, 2, 4 or 6 sets of three.

0 2-card + 6 3-card, 3 2-card+4 3-card, 6 2-card+2 3-card, 9 2-card+0 3-card. There are only 4 combinations:

(2-card, 3-card)=(0,6), (3,4), (6,2), (9,0).

5x+2x=49

7x=49

x=7. 35 apples

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.