This number is equal to four choose two, and it gives the number of possible meal combinations if you have two choices of entrée and three choices of dessert.
This is the number of ways to place two indistinguishable balls into three bins. This is the number of size two subsets of a set of four elements. Equivalently, this number is the coefficient of "x squared times y squared" in the expansion of "quantity x plus y to the fourth power." This number is the number of ways to order three distinct elements. This number is equal to four choose two, and it gives the number of possible meal combinations if you have two choices of entrée and three choices of dessert. For 10 points, name this number that is equal to three factorial.
This is the number of ways to place two indistinguishable balls into three bins.
{six} [accept {6}]