At a dinner party, 5 people are to be seated around a...

This topic has expert replies
Legendary Member
Posts: 2226
Joined: Sun Oct 29, 2017 2:04 pm
Followed by:6 members
At a dinners party, 5 people are seated around a circular table. 2 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 OA is C.

Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.

Master | Next Rank: 500 Posts
Posts: 415
Joined: Thu Oct 15, 2009 11:52 am
Thanked: 27 times

by regor60 » Tue Feb 27, 2018 9:53 am
swerve wrote:At a dinners party, 5 people are seated around a circular table. 2 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 OA is C.

Please, can any expert explain this PS question for me? I tried to solve it but I can't get the correct answer. I need your help. Thanks.
You can start by calculating the number of permutations of 5 people. For example, pick a chair to begin with. There are 5 ways to fill that chair. Continue clockwise with the remaining people, so :

5x4x3x2x1 = 120 arrangements

However, visualize that contributing to the total number of arrangements are arrangements where the same relative positioning of the five people is maintained but that each person is shifted one chair clockwise. Since question asks for those arrangements where only the relative positions are different, you need to divide 120 by 5 = 24,C

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7243
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Thu Mar 01, 2018 5:43 pm
swerve wrote:At a dinners party, 5 people are seated around a circular table. 2 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
When determining the number way to arrange a group around a circle, we subtract 1 from the total and set it to a factorial. Thus, the total number of possible sitting arrangements for 5 people around a circular table is 4! = 24.

Answer: C

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage