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GMAT Prep Exam

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GMAT Prep Exam

by janvierek » Sun Dec 02, 2007 4:03 pm
I need an explaination for the following GMAT prep question:

At a dinner party, 5 people are to be seated around a circular table. Two seating arrangements are considered different only when the positions of the people are different relative to each other. What is the total number of different possible seating arrangements for the group?

a) 5
b) 10
c) 24
d) 32
e) 120

the answer is C; but i don't understand how. Thanks

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by ri2007 » Sun Dec 02, 2007 5:30 pm
Ans is (5-1) factorial = 24

exp below

Circular permutations

There are two cases of circular-permutations:-

(a) If clockwise and anti clock-wise orders are different, then total number of circular-permutations is given by (n-1)!

(b) If clock-wise and anti-clock-wise orders are taken as not different, then total number of circular-permutations is given by (n-1)!/2!

for more details link is
https://www.google.com/search?hl=en&q=ci ... rrangement