GMAT Question of the Day - Daily to your Mailbox; hard ones only

 It is currently 19 Sep 2019, 18:29

### 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

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

# There are 5 couples. If they sit on 10 chairs around a round table suc

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

### Hide Tags

Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 7892
GMAT 1: 760 Q51 V42
GPA: 3.82
There are 5 couples. If they sit on 10 chairs around a round table suc  [#permalink]

### Show Tags

05 Feb 2018, 02:12
1
9
00:00

Difficulty:

55% (hard)

Question Stats:

48% (01:36) correct 52% (01:54) wrong based on 58 sessions

### HideShow timer Statistics

[GMAT math practice question]

There are 5 couples. If they sit on 10 chairs around a round table such that each couple sits side by side, how many possible cases are there?

A. 256
B. 512
C. 768
D. 1,024
E. 1,080

_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Intern
Joined: 30 Jul 2010
Posts: 1
Re: There are 5 couples. If they sit on 10 chairs around a round table suc  [#permalink]

### Show Tags

05 Feb 2018, 03:30
4
2
We can find in how many ways 5 objects may be placed around a circular table: (5-1)! = 4! = 24.
Then two people in each couple may sit in two ways (AB and BA), so we should multiply 24 by 2^5
24*32 = 768

##### General Discussion
Math Revolution GMAT Instructor
Joined: 16 Aug 2015
Posts: 7892
GMAT 1: 760 Q51 V42
GPA: 3.82
Re: There are 5 couples. If they sit on 10 chairs around a round table suc  [#permalink]

### Show Tags

07 Feb 2018, 00:47
1
1
=>

The number of arrangements of the 5 couples in a circle is (5-1)! = 4!. The members of each couple can be arranged in 2! ways.
Thus, the total number of arrangements is 4! * 2! * 2! * 2! * 2! * 2! = 24*2*2*2*2*2 = 768.

Therefore, the answer is C.

_________________
MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
"Only \$79 for 1 month Online Course"
"Free Resources-30 day online access & Diagnostic Test"
"Unlimited Access to over 120 free video lessons - try it yourself"
Non-Human User
Joined: 09 Sep 2013
Posts: 12399
Re: There are 5 couples. If they sit on 10 chairs around a round table suc  [#permalink]

### Show Tags

07 Aug 2019, 20:54
Hello from the GMAT Club BumpBot!

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.
_________________
Re: There are 5 couples. If they sit on 10 chairs around a round table suc   [#permalink] 07 Aug 2019, 20:54
Display posts from previous: Sort by

# There are 5 couples. If they sit on 10 chairs around a round table suc

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

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