SOLUTION: A club can select a president and a vice president from members in their club in 72 ways. How many members are in the club?

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Question 320497: A club can select a president and a vice president from members in their club in 72 ways. How many members are in the club?
Answer by Edwin McCravy(20054) About Me  (Show Source):
You can put this solution on YOUR website!

Suppose there are N club members.

We can choose the president as any of the N club members and the 
Vice-President any of the remaining N-1 club members, so:

N%2A%28N-1%29%22=%2272

N%5E2-N%22=%2272

N%5E2-N-72%22=%220

%28N-9%29%28N%2B8%29%22=%220



Disregard the negative solution.

There are 9 club members.

Edwin