combination of towels

Brian just told a funny story about towel in his blog, which reminded me of my curiosity about how our hotel manage their towels.

I am currently living in Ramada Inn, Memphis. When I first checked in, there were three complete sets of towels in my room, including 3 small square ones, 3 medium rectangular ones and 3 bathtowels.

Well, I didn't know that was the only day I got to see them together. Ever since then, the number of towels varied from zero (yesterday) to nine (last Monday) and the intriguing part is that the combination never repeated itself. Like today, I have 3 small towels, 1 medium one and 3 bathtowels.

I know it can be calculated how many combinations there could be, but I am too tired to do that. And I believe I won't stay here long enough to see all of that happens..