Two members of a certain club are selected to speak at the next club meeting. If there are 15 different possible selections of the 2 club members, how many members does the club have?	Select the correct option
A) 5	B) 6	C) 7	D) 8	E) 9
Method-1   Total No. of Selection of r out of n objects are defined by nCr = n! / [(r!)(n-r)!]   i.e. If total member = n   then nC2 = n! / [(2!)(n-2)!] = 15   i.e. n*(n-1)*n-2!/ [(2!)n-2!] = 15   i.e. n*(n-1) = 30   (for Positive Values of n)   therefore, n*(n-1) = 30   i.e. n= 6   Answer: Option 6
<result>B</result>
Two members of a certain club are selected to speak at the next club meeting. If there are 15 different possible selections of the 2 club members, how many members does the club have?