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 (average) of the nine remaining numbers is 6 ?
Answer Choices
A. 1
B. 2
C. 3
D. 5
E. 6
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 (average) of the nine remaining numbers is 6 ?
Answer Choices
A. 1
B. 2
C. 3
D. 5
E. 6