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

It is currently 21 Mar 2019, 13:21

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

On the occasion of a certain meeting, each member exchanged shake hand

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

Hide Tags

 
Manager
Manager
avatar
S
Joined: 26 Nov 2018
Posts: 72
Location: Bangladesh
Concentration: Technology, Entrepreneurship
GPA: 3.3
WE: Manufacturing and Production (Manufacturing)
GMAT ToolKit User
On the occasion of a certain meeting, each member exchanged shake hand  [#permalink]

Show Tags

New post 04 Mar 2019, 07:22
2
1
00:00
A
B
C
D
E

Difficulty:

  35% (medium)

Question Stats:

67% (01:13) correct 33% (01:35) wrong based on 9 sessions

HideShow timer Statistics

On the occasion of a certain meeting, each member exchanged shake hand with one another. If the total shake hands were 21, then how many members are there in the meeting?

A. 6
B. 5
C. 7
D. 4
E. 3
Intern
Intern
avatar
B
Joined: 21 Feb 2019
Posts: 36
Re: On the occasion of a certain meeting, each member exchanged shake hand  [#permalink]

Show Tags

New post 04 Mar 2019, 09:50
2
If there are \(n\) people,the first one will have \((n-1)\) handshakes (all except himself).
The second one will have \(n -2\) handshakes (the first person has already been counted for). And so on...

We obtain:

\(\frac{n(n-1)}{2} = 21\)

\(n^2 - n -42 = 0\)

\((n - 7) (n + 6) = 0\)

\(n = 7\)
_________________

If you liked my post, give me Kudos! Thank you.

GMAT Club Bot
Re: On the occasion of a certain meeting, each member exchanged shake hand   [#permalink] 04 Mar 2019, 09:50
Display posts from previous: Sort by

On the occasion of a certain meeting, each member exchanged shake hand

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


Copyright

GMAT Club MBA Forum Home| About| Terms and Conditions and Privacy Policy| 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®.