It is currently 20 Oct 2017, 13:20

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

If 6 people are going to sitting at a round table, but Sam will not si

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:

Hide Tags

3 KUDOS received
VP
VP
User avatar
D
Joined: 14 Nov 2016
Posts: 1161

Kudos [?]: 1182 [3], given: 415

Location: Malaysia
GMAT ToolKit User Premium Member CAT Tests
If 6 people are going to sitting at a round table, but Sam will not si [#permalink]

Show Tags

New post 29 Jul 2017, 21:34
3
This post received
KUDOS
5
This post was
BOOKMARKED
00:00
A
B
C
D
E

Difficulty:

  55% (hard)

Question Stats:

39% (01:01) correct 61% (00:53) wrong based on 69 sessions

HideShow timer Statistics

If 6 people are going to sitting at a round table, but Sam will not sit next to Suzie, how many different ways can the group of 6 sit?

(A) 120
(B) 108
(C) 96
(D) 72
(E) 56
[Reveal] Spoiler: OA

_________________

"Be challenged at EVERY MOMENT."

“Strength doesn’t come from what you can do. It comes from overcoming the things you once thought you couldn’t.”

"Each stage of the journey is crucial to attaining new heights of knowledge."

Rules for posting in verbal forum | Please DO NOT post short answer in your post!

Kudos [?]: 1182 [3], given: 415

Expert Post
2 KUDOS received
Math Forum Moderator
avatar
P
Joined: 02 Aug 2009
Posts: 4981

Kudos [?]: 5486 [2], given: 112

Re: If 6 people are going to sitting at a round table, but Sam will not si [#permalink]

Show Tags

New post 29 Jul 2017, 21:50
2
This post received
KUDOS
Expert's post
hazelnut wrote:
If 6 people are going to sitting at a round table, but Sam will not sit next to Suzie, how many different ways can the group of 6 sit?

(A) 120
(B) 108
(C) 96
(D) 74
(E) 56



Hi...
6 people can be arranged in (6-1)!=120ways
Now let sam and Suzie be sitting together and hence there are 5 people
Ways = (5-1)!*2=4!*2=48.... Multiplication by 2 is cater for sam-suzane and suzane-sam..

Ways they don't sit together=120-48=72..
hazelnut, D may be 72 and not 74..
_________________

Absolute modulus :http://gmatclub.com/forum/absolute-modulus-a-better-understanding-210849.html#p1622372
Combination of similar and dissimilar things : http://gmatclub.com/forum/topic215915.html

Kudos [?]: 5486 [2], given: 112

Manager
Manager
avatar
B
Joined: 07 Jun 2017
Posts: 111

Kudos [?]: 3 [0], given: 454

Re: If 6 people are going to sitting at a round table, but Sam will not si [#permalink]

Show Tags

New post 30 Jul 2017, 09:10
chetan2u wrote:
hazelnut wrote:
If 6 people are going to sitting at a round table, but Sam will not sit next to Suzie, how many different ways can the group of 6 sit?

(A) 120
(B) 108
(C) 96
(D) 74
(E) 56



Hi...
6 people can be arranged in (6-1)!=120ways
Now let sam and Suzie be sitting together and hence there are 5 people
Ways = (5-1)!*2=4!*2=48.... Multiplication by 2 is cater for sam-suzane and suzane-sam..

Ways they don't sit together=120-48=72..
hazelnut, D may be 72 and not 74..


Dear,
I don't understand why it is 5! way to seat 6 people.
and I don't get how do you get 48 way for not siting together :(
Sorry, I really wanna know

Kudos [?]: 3 [0], given: 454

1 KUDOS received
Manager
Manager
avatar
S
Joined: 19 Dec 2016
Posts: 59

Kudos [?]: 43 [1], given: 51

Location: India
Concentration: Technology, Leadership
WE: Consulting (Computer Software)
If 6 people are going to sitting at a round table, but Sam will not si [#permalink]

Show Tags

New post 01 Aug 2017, 12:05
1
This post received
KUDOS
1
This post was
BOOKMARKED
pclawong wrote:
chetan2u wrote:
hazelnut wrote:
If 6 people are going to sitting at a round table, but Sam will not sit next to Suzie, how many different ways can the group of 6 sit?

(A) 120
(B) 108
(C) 96
(D) 74
(E) 56



Hi...
6 people can be arranged in (6-1)!=120ways
Now let sam and Suzie be sitting together and hence there are 5 people
Ways = (5-1)!*2=4!*2=48.... Multiplication by 2 is cater for sam-suzane and suzane-sam..

Ways they don't sit together=120-48=72..
hazelnut, D may be 72 and not 74..


Dear,
I don't understand why it is 5! way to seat 6 people.
and I don't get how do you get 48 way for not siting together :(
Sorry, I really wanna know


Hi pclawong

i think i can help you with this.

first of all if 6 people are sitting around a table, and the condition is Sam will not sit next to Suzie.

this will be equal to total no. of ways 6 people can sit around a table - total no of ways in which Sam will always sit next to Suzie

now total no of ways, 6 people can sit around a circular table is (6-1)!
and total no of ways, Sam will always sit next to Suzie is (5-1)! 2!

Note: total no. of ways in which n different things can be arranged around a circular path is (n-1)!

now let me tell you why we are doing (5-1)! 2! for the later case-

in later case we are assuming that Sam will always sit next to Suzie, so we are considering them as a single unit saying that now we have 5 people not 6.

now number of way, 5 people can sit around a circular table is (5-1)!

now again Sam & Suzie can interchange their position so we are doing 2! for them

so now total no. of ways, Sam will always sit next to Suzie is (5-1)! 2!

now the question is asking about ways in which Sam will not sit next to Suzie.

we subtract (5-1)! 2! into total no of ways which is (6-1)!

(6-1)! - (5-1)! 2!

hope this will help you.
_________________

If you want to appreciate, just click on Kudos.


Last edited by GTExl on 01 Aug 2017, 12:10, edited 1 time in total.

Kudos [?]: 43 [1], given: 51

Manager
Manager
avatar
B
Joined: 07 Jun 2017
Posts: 111

Kudos [?]: 3 [0], given: 454

Re: If 6 people are going to sitting at a round table, but Sam will not si [#permalink]

Show Tags

New post 02 Aug 2017, 21:19
Thank you GTExl
I get it now after combined you both explanation.
God bless you :-D

Kudos [?]: 3 [0], given: 454

Re: If 6 people are going to sitting at a round table, but Sam will not si   [#permalink] 02 Aug 2017, 21:19
Display posts from previous: Sort by

If 6 people are going to sitting at a round table, but Sam will not si

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


cron

GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.