For whatever reason (maybe I'm retarded) I'm just not following it.
While trick or treating in Clayton, NY (population 1,978), some friends play a counting game-they counted all the houses they visited while trick or treating (they all counted the same houses). Diego counted the houses by 5's, and had four houses left at the end. Madeline counted the houses by 7's, and had six houses left over at the end. Based on Diego's and Madeline's counts, how many houses did they visit? Is this the only possible answer? Explain why you are sure you found all possible counts.