Jonathan and Tori are collecting creatures for a science project. So far they have spiders, flies, and worms. Mr. Sims, their science teacher, asked them how many of each they had. Having just come from algebra class, they said, "We have 18 creatures in all, and the total number of legs if 68." Can Mr. Sims determine how many spiders, flies, and worms Jonathan and Tiana have? Is there more than one possible solution to the problem?