Two members of a club are to be selected to represent the club at a national meeting. if there are 55 different possible selections of the 2 members, how many members does the club have?
Choose the correct choice from the following answers:
A) 11
B) 27
C) 40
D) 57
E) 95
I have done this problem by substituting numbers   We have n!/2!(n-2)! = 55   or n(n-1)/2 = 110 or n^2-n -110 =0 or n^2-11n+10n-110 =0 or n(n-11) +10(n-11) =0 or (n-11)(n+10)=0   n=11 satisfies the equation   11
<result>A</result>
Two members of a club are to be selected to represent the club at a national meeting. if there are 55 different possible selections of the 2 members, how many members does the club have?