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

It is currently 23 Jul 2014, 00:38

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 committee of 3 people is to be formed from 4 married

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 10 Apr 2006
Posts: 33
Followers: 0

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

GMAT Tests User
A committee of 3 people is to be formed from 4 married [#permalink] New post 26 Dec 2006, 18:55
A committee of 3 people is to be formed from 4 married couples. What is the number of different committees that can be chosen if 2 people who are married to each other cannot both serve on the committee ?

a. 16
b. 24
c. 26
d. 30
e. 32
Intern
Intern
avatar
Joined: 10 Apr 2006
Posts: 33
Followers: 0

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

GMAT Tests User
 [#permalink] New post 26 Dec 2006, 19:24
Appuvar you got it right ..... OA is E but how did you get to it ?
Director
Director
avatar
Joined: 24 Aug 2006
Posts: 754
Location: Dallas, Texas
Followers: 5

Kudos [?]: 21 [0], given: 0

GMAT Tests User
Re: committee of couples [#permalink] New post 26 Dec 2006, 19:25
vmalaiya wrote:
A committee of 3 people is to be formed from 4 married couples. What is the number of different committees that can be chosen if 2 people who are married to each other cannot both serve on the committee ?

a. 16
b. 24
c. 26
d. 30
e. 32


(AA1) (BB1) (CC1) (DD1)

The first person can be selected 8 different ways.
The second person can be selected 6 different ways. (if you selected A, you can't select A1).
The third person can be selected 4 different ways (if you selected B in second attempt , you can't select B1)

ABC1 and C1AB are same since order doesn't matter.
Therefore number of committees = (8*6*4)/3! =32

(E) is my answer.

_________________

"Education is what remains when one has forgotten everything he learned in school."

VP
VP
avatar
Joined: 21 Mar 2006
Posts: 1136
Location: Bangalore
Followers: 2

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

GMAT Tests User
 [#permalink] New post 26 Dec 2006, 19:46
Number of possible combinations of the committee = 8C3 = 56
Number of ways in which one couple can be a part of the committee = 1 * 6

<1 for the couple who will fill 2 seats on the committe. 6 for the ways in which the remaning seat can be filled>

Thus for 4 couples, the number of ways in which a couple can be a part of the committee = 6 * 4 = 24

Thus, number of ways a couple cannot be a part of the committee =
(Total number of combinations) - (no of comb a couple is on the committee)

= 56 - 24 = 32.

Give me E!
Manager
Manager
avatar
Joined: 22 Oct 2006
Posts: 76
Location: India
Followers: 1

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

 [#permalink] New post 27 Dec 2006, 08:35
I used the same logic that Kripalkavi used.

8C3 - 4*6C1 = 56-24=32!
Senior Manager
Senior Manager
avatar
Joined: 23 Jun 2006
Posts: 389
Followers: 1

Kudos [?]: 298 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Dec 2006, 09:12
nice counting everybody....

here is another way to count it, gives the same answer:

first, let choose the three couples (out of 4) that send a representative to the committee... ok there are 4 ways to do that.
now for each couple, independently choose its representative. total of 2 options per couple gives us: 2*2*2=8
multiply the two gives you the right answer.
VP
VP
avatar
Joined: 28 Mar 2006
Posts: 1390
Followers: 2

Kudos [?]: 18 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Dec 2006, 15:24
hobbit wrote:
nice counting everybody....

here is another way to count it, gives the same answer:

first, let choose the three couples (out of 4) that send a representative to the committee... ok there are 4 ways to do that.
now for each couple, independently choose its representative. total of 2 options per couple gives us: 2*2*2=8
multiply the two gives you the right answer.


You COUNT so well hobbit :-D .....Wow thats pretty neat...
Senior Manager
Senior Manager
avatar
Joined: 23 Jun 2006
Posts: 389
Followers: 1

Kudos [?]: 298 [0], given: 0

GMAT Tests User
 [#permalink] New post 27 Dec 2006, 16:48
trivikram wrote:
You COUNT so well hobbit :-D .....Wow thats pretty neat...


actually, everybody here did good job as well.... but thanks for the compliment anyway.

there are always so many ways to count things... so there is no right/wrong way, and sometimes what is easy and intuitive for one is difficult for another....

the only principles common to all is: count cautiously. make sure you count every possibility. make sure you don't count a certain possibility more than once. use formulas just if you really sure you need them - i.e. "irreducible" counting tasks... and have fun...

beside that there are just few more "thumb rules" that you learn from experience...

i had once a long post on counting.

anyway.... good counting everybody :)
VP
VP
User avatar
Joined: 25 Jun 2006
Posts: 1176
Followers: 2

Kudos [?]: 31 [0], given: 0

GMAT Tests User
 [#permalink] New post 28 Dec 2006, 21:10
do a search. this is posted several times.
  [#permalink] 28 Dec 2006, 21:10
    Similar topics Author Replies Last post
Similar
Topics:
1 Experts publish their posts in the topic A committee of three people is to be chosen from 4 married alimad 16 18 Nov 2007, 19:15
26 Experts publish their posts in the topic A committee of 3 people is to be chosen from four married LM 34 11 May 2010, 11:35
A committee of 3 people is to be chosen from 4 married tharunv 1 30 Oct 2008, 17:37
A committee of 3 people is to be chosen from four married chadhazen6 2 03 Oct 2006, 16:49
A committee of 3 people is to be chosen from four married positive_energy 4 01 Aug 2006, 04:11
Display posts from previous: Sort by

A committee of 3 people is to be formed from 4 married

  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®.