Answer
2, 6, $(n-1)!$
Work Step by Step
As the people will form a circle, we can fix one position and
think the problem as arranging the rest $n-1$ members.
The next seat after fixing the first one has $n-1$ choices, and
the next one $n-2$ choices and so on.
So the total number of ways is: $(n-1)!$
For example, n=3, #ways = 2; n=4, #ways=6, etc.
