How many ways can 4 friends be arranged around a circular dinner table?  Choose the correct choice
A) A)6 B) B)48 C) C)96 D) D)120 E) E)720
The number of arrangements of n distinct objects in a row is given by n!n!.   The number of arrangements of n distinct objects in a circle is given by (n−1)!(n−1)!.   The difference between placement in a row and that in a circle is following: if we shift all object by one position, we will get different arrangement in a row but the same relative arrangement in a circle. So, for the number of circular arrangements of n objects we have:   n!n=(n−1)!n!n=(n−1)!.   So, the answer is (4 - 1)= 
<gadget id="calculator">(4 - 1)</gadget>
<output>3</output>
3!= 6.   6nswer: 6.
<result>A</result>
How many ways can 4 friends be arranged around a circular dinner table?