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

It is currently 26 Jul 2014, 11:44

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

A certain law firm consists of 4 senior partners and 6

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Director
Director
User avatar
Joined: 08 Jun 2004
Posts: 502
Location: Europe
Followers: 1

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

GMAT Tests User
A certain law firm consists of 4 senior partners and 6 [#permalink] New post 14 May 2006, 04:42
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 1 sessions
A certain law firm consists of 4 senior partners and 6 junior partners. How many different groups of 3 partners can be formed in which at least one number of the group is a senior partner? (Two groups are considered different if at least one group member is different).

A. 48
B. 100
C. 120
D. 288
E. 600
Director
Director
avatar
Joined: 16 Aug 2005
Posts: 950
Location: France
Followers: 1

Kudos [?]: 8 [0], given: 0

GMAT Tests User
 [#permalink] New post 14 May 2006, 12:24
I got this question in my GMATPrep exam today and got it right

B
Director
Director
User avatar
Joined: 08 Jun 2004
Posts: 502
Location: Europe
Followers: 1

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

GMAT Tests User
 [#permalink] New post 14 May 2006, 19:37
Hey Prof is my approach correct? Thank you.
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5097
Location: Singapore
Followers: 16

Kudos [?]: 131 [0], given: 0

GMAT Tests User
 [#permalink] New post 14 May 2006, 19:42
Combis:

3 senior partner ---> # of ways = 4C3 = 4
2 senior partner + 1 junior partner ---> # of ways = 4C2*6C1 = 6*6 = 36
1 senior partner + 2 junior partner ---> # of ways = 4C1*6C2 = 4*15 = 60

Total = 4+36+60 = 100 groups
GMAT Club Legend
GMAT Club Legend
User avatar
Joined: 07 Jul 2004
Posts: 5097
Location: Singapore
Followers: 16

Kudos [?]: 131 [0], given: 0

GMAT Tests User
 [#permalink] New post 14 May 2006, 19:44
M8 wrote:
Guys what about 10C3 - 4C1*6C1?


What is your basis for picking 4C1 and 6C1. You're just picking 1 senior partner and 1 junior partner, so you'll still be one man short.

The correct method should be 10C3 - 6C3 = 120-20 = 100. We use 6C3 because 3 junior partners in the group is an illegal condition.
VP
VP
User avatar
Joined: 29 Dec 2005
Posts: 1351
Followers: 6

Kudos [?]: 27 [0], given: 0

GMAT Tests User
 [#permalink] New post 15 May 2006, 16:34
M8 wrote:
Guys what about 10C3 - 4C1*6C1?


=10C3 - 4C1*6C1 = 120 - 24 = 96 is not correct because 4C1*6C1 means you are selecting each senoir and junior from 4 seniors and 6 juniors. why should we choose 2 (s+j) from 10?

you can do as deowl did.

=10C3 - 6C3
=120-20
=100
  [#permalink] 15 May 2006, 16:34
    Similar topics Author Replies Last post
Similar
Topics:
1 A certain law firm consists of 4 senior partners and 6 lionheart187 7 31 Aug 2008, 11:03
A certain law firm consists of 4 senior partners and 6 japped187 1 14 May 2008, 16:35
12 Experts publish their posts in the topic A certain law firm consists of 4 senior partners and 6 alimad 13 19 Nov 2007, 05:21
1 A certain law firm consists of 4 senior partners and 6 gnr646 4 10 Sep 2007, 04:52
A certain law firm consists of 4 senior partners and 6 getzgetzu 3 22 Jul 2006, 05:07
Display posts from previous: Sort by

A certain law firm consists of 4 senior partners and 6

  Question banks Downloads My Bookmarks Reviews Important topics  


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®.