选择题
2015 AMC 8 Problem 13: Remove Two for Mean Six
How many subsets of two elements can be removed from the set {1,2,3,4,5,6,7,8,9,10,11} so that the mean of the remaining numbers is 6?
2015 AMC 8 第13题：去除 2 以获得平均 6
可以从集合 {1,2,3,4,5,6,7,8,9,10,11} 中删除两个元素的多少个子集，使得剩余数字的平均值为 6
A.
1
B.
2
C.
3
D.
5
E.
6