3 representative from 6 companies. shake hands only with : PS Archive
Check GMAT Club Decision Tracker for the Latest School Decision Releases http://gmatclub.com/AppTrack

 It is currently 18 Jan 2017, 08:29

### 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

# Events & Promotions

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

# 3 representative from 6 companies. shake hands only with

Author Message
CEO
Joined: 15 Aug 2003
Posts: 3460
Followers: 67

Kudos [?]: 862 [0], given: 781

3 representative from 6 companies. shake hands only with [#permalink]

### Show Tags

13 Sep 2003, 05:38
00:00

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions

### HideShow timer Statistics

This topic is locked. If you want to discuss this question please re-post it in the respective forum.

3 representative from 6 companies. shake hands only with other
companies' representative. representative from same company does not
shake hands. how many hand shakes?

Check my work

Total # of handshakes = 18 * 17 = 306

We double count the handshakes and also count those amongst representatives ...

Dividing by 2 ...So total handshakes = 306/2 =153

For Handshakes amongst representatives...
Three people => Handshakes= 3*2/2 = 3
For six companies = > total handshakes = 6 * 3 =18

153 - 18 = 135 ..Is this correct?

thanks
Senior Manager
Joined: 22 May 2003
Posts: 333
Location: Uruguay
Followers: 1

Kudos [?]: 145 [0], given: 0

### Show Tags

13 Sep 2003, 20:45
I guess so. I got the same answer.

I did 3*(3*5+3*4+3*3+2*3+3)=3*(15+12+9+6+3)=135
Intern
Joined: 13 Sep 2003
Posts: 43
Location: US
Followers: 0

Kudos [?]: 30 [0], given: 0

### Show Tags

04 Nov 2003, 08:45
another way to look at the same problem:

for any handshake u need 2 persons.

so total number of handshakes between 18 ppl = 18C2 = 153 .
Now within the group ; 3C2 = 3.
Total groups 6 so 6*3 = 18.

Now total valid handshakes for this scenario is 153- 18 = 135.
Intern
Joined: 13 Sep 2003
Posts: 43
Location: US
Followers: 0

Kudos [?]: 30 [0], given: 0

### Show Tags

10 Nov 2003, 09:20
1.Number of handshakes between n people is n(n-1)/2.

2.Number of diagnols of a polygon with n sides = n(n-1)/2 - n.
formula   [#permalink] 10 Nov 2003, 09:20
Display posts from previous: Sort by