Find all School-related info fast with the new School-Specific MBA Forum

 It is currently 25 Jul 2016, 23:54

### 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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# If 10 persons meet at a reunion and each person shakes hands

Author Message
TAGS:

### Hide Tags

Manager
Joined: 10 Feb 2011
Posts: 114
Followers: 1

Kudos [?]: 188 [0], given: 10

If 10 persons meet at a reunion and each person shakes hands [#permalink]

### Show Tags

09 Mar 2011, 15:12
2
This post was
BOOKMARKED
00:00

Difficulty:

5% (low)

Question Stats:

73% (01:26) correct 27% (00:34) wrong based on 255 sessions

### HideShow timer Statistics

If 10 persons meet at a reunion and each person shakes hands exactly once with each of the others, what is the total number of handshakes?
(A) 10•9•8•7•6•5•4•3•2•1
(B) 10•10
(C) 10•9
(D) 45
(E) 36
[Reveal] Spoiler: OA
Math Expert
Joined: 02 Sep 2009
Posts: 34059
Followers: 6084

Kudos [?]: 76471 [2] , given: 9975

Re: . If 10 persons meet at a reunion and each person shakes han [#permalink]

### Show Tags

09 Mar 2011, 15:20
2
KUDOS
Expert's post
banksy wrote:
. If 10 persons meet at a reunion and each person shakes hands exactly once with each of the others, what is the total number of handshakes?
(A) 10•9•8•7•6•5•4•3•2•1
(B) 10•10
(C) 10•9
(D) 45
(E) 36

The total # of handshakes will be equal to the # of different pairs possible from these 10 people (one handshake per pair), so $$C^2_{10}=45$$.

_________________
Intern
Status: Going the extra mile
Joined: 08 Feb 2014
Posts: 20
Location: Netherlands
GMAT 1: 470 Q37 V18
GMAT 2: 570 Q36 V32
GMAT 3: 560 Q37 V30
GMAT 4: 610 Q41 V34
Followers: 0

Kudos [?]: 12 [1] , given: 57

Re: If 10 persons meet at a reunion and each person shakes hands [#permalink]

### Show Tags

29 Apr 2014, 12:17
1
KUDOS
We got #10 people who shake each other's hands once ==> a pair of 2

10!/8!2! = 10*9 / 2*1 = 45.

_________________

Structural persistence is the key to succes .
Party hard, study harder.

Still bashing, will continue to do so , although it's important to chill aswell ; )
STUDY+CHILL=VICTORY

GMAT Club Legend
Joined: 09 Sep 2013
Posts: 10596
Followers: 495

Kudos [?]: 129 [0], given: 0

Re: If 10 persons meet at a reunion and each person shakes hands [#permalink]

### Show Tags

16 Sep 2015, 16:56
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.
_________________
Optimus Prep Instructor
Joined: 06 Nov 2014
Posts: 1598
Followers: 40

Kudos [?]: 322 [0], given: 20

Re: If 10 persons meet at a reunion and each person shakes hands [#permalink]

### Show Tags

16 Sep 2015, 21:03
Expert's post
Handshakes are made in a pair of 2
Hence the total handshakes = total different different pairs

This can be found by 10C2= 10!/8!*2!

On solving , we get 45 (Option D)
_________________

# Janielle Williams

Customer Support

Special Offer: $80-100/hr. Online Private Tutoring GMAT On Demand Course$299
Free Online Trial Hour

Re: If 10 persons meet at a reunion and each person shakes hands   [#permalink] 16 Sep 2015, 21:03
Similar topics Replies Last post
Similar
Topics:
2 6 people meet for a business lunch. Each person shakes hands once with 3 12 May 2016, 01:56
3 Each person who attended a company meeting was either a stockholder in 1 14 Sep 2015, 08:36
7 If 11 persons meet at a reunion and each person shakes hands exactly o 8 08 Dec 2014, 06:26
3 Each person who attended a company meeting was either a 6 26 Apr 2012, 03:51
3 There are 10 people in a room. If each person shakes hands with exactl 11 25 Nov 2010, 19:05
Display posts from previous: Sort by