求解 为什么不是21中可能性呢

alice5678

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

naturalwater

各取一样＋各取两样
C(2,1)C(6,1)+C(6,2)C(2,2)=27

姿姿不倦

可以有两种cheese和两种水果。
也可以分别只有一种