A certain restaurant offers 6 kinds of cheese and 2 kinds of fruit for its dessert platter. If each dessert platter contains an equal number of kinds of cheese and kinds of fruit, how many different dessert platters could the restaurant offer?
8
12
15
21
27
两种情况
水果和奶酪数量要一样,所以是要么都只有一种,要么都只有两种,一种的是C(6,1) *2,两种的是C(6,2) * C(2,2)
水果和奶酪数量要一样,所以是要么都只有一种,要么都只有两种,一种的是6*2,两种的是c6 2 * c 2 2
6*2+C6 2
这道题怎么做哦