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

It is currently 19 Apr 2014, 07:31

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.

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

m07 #27

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
Joined: 03 Oct 2012
Posts: 10
Location: India
Concentration: General Management, Entrepreneurship
Schools: Tepper '16 (S)
GMAT 1: 620 Q50 V25
GMAT 2: 680 Q50 V31
GRE 1: 314 Q166 V148
GPA: 3.44
WE: Operations (Computer Software)
Followers: 0

Kudos [?]: 5 [0], given: 19

GMAT ToolKit User
Re: m07 #27 [#permalink] New post 15 Aug 2013, 09:47
Every B.E meets every other person!
10(ways to select a B.E)*16(selecting one other person from the whole = 160

Every C meets every B.E
10*7 = 70

Total= 160+70=330

But our answer should be independent of order, i.e., A meeting B, is same as B meeting A.

Hence correct answer is total / 2

Hence
115









---------------------

bipolarbear wrote:
10 business executives and 7 chairmen meet at a conference. If each business executive shakes the hand of every other business executive and every chairman once, and each chairman shakes the hand of each of the business executives but not the other chairmen, how many handshakes would take place?

(A) 144
(B) 131
(C) 115
(D) 90
(E) 45

[Reveal] Spoiler: OA
C

Source: GMAT Club Tests - hardest GMAT questions

[Reveal] Spoiler: OE
Chairmen shake hands 10*7=70 with business executives times. Business executives shake hands with each other 10 C 2 times or 45 times. The total is 115 .


Can someone explain to me why its 10 C 2?
Kaplan Promo CodeKnewton GMAT Discount CodesManhattan GMAT Discount Codes
Intern
Intern
Joined: 30 May 2013
Posts: 14
Followers: 0

Kudos [?]: 2 [0], given: 2

GMAT ToolKit User
Re: m07 #27 [#permalink] New post 15 Aug 2013, 14:14
hello,

could someone please explain this one thing to me.

When 10 execs shake hand with each other we say 10*9/2 as the order does no matter.

But when we do 7 chairman shaking hands with 10 execs, we are saying 7*10. Why aren't we dividing this by 2?

Adi
Intern
Intern
Joined: 13 Aug 2013
Posts: 7
Followers: 0

Kudos [?]: 2 [0], given: 0

Re: m07 #27 [#permalink] New post 16 Aug 2013, 01:03
Hand Shakes among the business executive and chairmen - 10c1 x 7c1 = 70
Hand Shakes among the executives alone- 10c2 =45
total- 115 hand shakes
1 KUDOS received
Intern
Intern
Joined: 13 Aug 2013
Posts: 7
Followers: 0

Kudos [?]: 2 [1] , given: 0

Re: m07 #27 [#permalink] New post 16 Aug 2013, 01:12
1
This post received
KUDOS
makhija1 wrote:
hello,

could someone please explain this one thing to me.

When 10 execs shake hand with each other we say 10*9/2 as the order does no matter.

But when we do 7 chairman shaking hands with 10 execs, we are saying 7*10. Why aren't we dividing this by 2?

Adi

This is essentially because executives and a chairmen are a different set of people. We are just selecting one from each group (selecting one from executives 10c1 and one from chirmen 7c1) . And hence the cases. 10c1 x 7c1. Whereas executives is a single group and we need to select two people from the same group for the handshake, hence 10c2
Re: m07 #27   [#permalink] 16 Aug 2013, 01:12
    Similar topics Author Replies Last post
Similar
Topics:
Popular new posts 1 m07q18 abhaypratapsingh 16 23 Jul 2008, 04:58
Popular new posts M07: Q25 tamg08 10 25 Aug 2008, 18:36
Popular new posts 6 Experts publish their posts in the topic m07 #22 michael127 18 03 Sep 2008, 18:41
Popular new posts 3 Experts publish their posts in the topic m07 q33 mbafwi 10 08 Sep 2008, 10:39
Popular new posts 16 Experts publish their posts in the topic M07 #2 dczuchta 15 25 Sep 2008, 10:35
Display posts from previous: Sort by

m07 #27

  Question banks Downloads My Bookmarks Reviews Important topics  

Go to page   Previous    1   2   [ 24 posts ] 

Moderators: Bunuel, WoundedTiger



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

Powered by phpBB © phpBB Group and phpBB SEO

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®.