Suppose a potter has 10 choices of glazes to apply on her pottery. She knows that if she applies glaze A OVER glaze B, it may not look the same as applying glaze B OVER glaze A. She wants to test the effect of combining these glazes by dipping a small vessel into 3 of these glazes. She will dip deeply into the first glaze (to see how it looks alone), then less deep into the next glaze (to see how it looks when applied OVER the first glaze) and then barely dip into the third glaze (to see how it looks when applied OVER the previous two glazes).

How many possible test vessels can be glazed?