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

It is currently 04 Aug 2015, 02:54
GMAT Club Tests

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

Combinations

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Senior Manager
Senior Manager
User avatar
Joined: 01 Feb 2005
Posts: 274
Followers: 1

Kudos [?]: 40 [0], given: 1

Combinations [#permalink] New post 05 Feb 2009, 17:48
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

Please see the attachment... Please explain the answer...
Attachments

untitled.GIF
untitled.GIF [ 8.33 KiB | Viewed 912 times ]

SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1824
Location: New York
Followers: 29

Kudos [?]: 573 [0], given: 5

Re: Combinations [#permalink] New post 05 Feb 2009, 18:46
axl_oz wrote:
Please see the attachment... Please explain the answer...



10C3*10C3
= 10*9*8/(1*2*3) *10*9*8/(1*2*3)
= 120*120 = 14400
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

Manager
Manager
avatar
Joined: 13 Jan 2009
Posts: 172
Schools: Harvard Business School, Stanford
Followers: 4

Kudos [?]: 18 [0], given: 9

Re: Combinations [#permalink] New post 05 Feb 2009, 22:01
x2suresh, can you please explain your answer? Thanks!!!
SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1824
Location: New York
Followers: 29

Kudos [?]: 573 [0], given: 5

Re: Combinations [#permalink] New post 05 Feb 2009, 22:45
Ibodullo wrote:
x2suresh, can you please explain your answer? Thanks!!!


10 - Republicans
10 - Democrates

Answ= No of Ways choose 3 R out of 10 R * No of Ways choose 3 D out of 10 D
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

Manager
Manager
avatar
Joined: 04 Jan 2009
Posts: 241
Followers: 1

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

Re: Combinations [#permalink] New post 06 Feb 2009, 09:28
x2suresh wrote:
Ibodullo wrote:
x2suresh, can you please explain your answer? Thanks!!!


10 - Republicans
10 - Democrates

Answ= No of Ways choose 3 R out of 10 R * No of Ways choose 3 D out of 10 D

why would be 10x9x8x10x9x8 wrong?
_________________

-----------------------
tusharvk

SVP
SVP
User avatar
Joined: 07 Nov 2007
Posts: 1824
Location: New York
Followers: 29

Kudos [?]: 573 [0], given: 5

Re: Combinations [#permalink] New post 06 Feb 2009, 10:01
tusharvk wrote:
x2suresh wrote:
Ibodullo wrote:
x2suresh, can you please explain your answer? Thanks!!!


10 - Republicans
10 - Democrates

Answ= No of Ways choose 3 R out of 10 R * No of Ways choose 3 D out of 10 D

why would be 10x9x8x10x9x8 wrong?


You are using Permutations.. that's valid if order matters..

e.g. consider you have group of 3 repuplicans.. R1 R2 R3
how many ways you will select 2 Repulicans out of 3
Is it 3P2 or 3C2??? will see..

Your answer = 3P2 = 3*2 =6 ways
A1 A2 --A2 A1 <duplicate>
A2 A3 --A3 A2 <duplicate>
A3 A1 --A1 A3 <duplicate>

My answer = 3C2 = 3*2/2! = 3 ways.
A1 A2 =A2 A1
A2 A3 =A3 A2
A3 A1 =A1 A3




Did you get it
_________________

Your attitude determines your altitude
Smiling wins more friends than frowning

SVP
SVP
User avatar
Joined: 29 Aug 2007
Posts: 2493
Followers: 59

Kudos [?]: 584 [0], given: 19

Re: Combinations [#permalink] New post 06 Feb 2009, 11:08
axl_oz wrote:
Please see the attachment... Please explain the answer...


The question clearly says combination. so permutation doesnot aapply to this case.

No of ways the cgroup can be made = 10c3 x 10c3 = 14,400
_________________

Verbal: new-to-the-verbal-forum-please-read-this-first-77546.html
Math: new-to-the-math-forum-please-read-this-first-77764.html
Gmat: everything-you-need-to-prepare-for-the-gmat-revised-77983.html


GT

Re: Combinations   [#permalink] 06 Feb 2009, 11:08
Display posts from previous: Sort by

Combinations

  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®.