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

It is currently 16 Sep 2014, 09:31

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

What are the total number of ways, in which 3 red and 3 blue

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Senior Manager
Senior Manager
avatar
Joined: 02 Mar 2004
Posts: 330
Location: There
Followers: 1

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

GMAT Tests User
What are the total number of ways, in which 3 red and 3 blue [#permalink] New post 12 May 2004, 17:53
00:00
A
B
C
D
E

Difficulty:

(N/A)

Question Stats:

0% (00:00) correct 0% (00:00) wrong based on 0 sessions
What are the total number of ways, in which 3 red and 3 blue beads can be put in a circular bracelet?
SVP
SVP
User avatar
Joined: 30 Oct 2003
Posts: 1798
Location: NewJersey USA
Followers: 4

Kudos [?]: 34 [0], given: 0

GMAT Tests User
 [#permalink] New post 12 May 2004, 19:58
3 ways assuming all red beads are identical and all blue beads are identical

Following ways are possible
BBBRRR - You can rotate them to get different combinations
BBRBRR
BRBRBR
These 3 basics arrangements cover all possible arrangements
GMAT Club Legend
GMAT Club Legend
avatar
Joined: 15 Dec 2003
Posts: 4318
Followers: 22

Kudos [?]: 163 [0], given: 0

GMAT Tests User
 [#permalink] New post 12 May 2004, 20:29
anandnk wrote:
3 ways assuming all red beads are identical and all blue beads are identical

Following ways are possible
BBBRRR - You can rotate them to get different combinations
BBRBRR
BRBRBR
These 3 basics arrangements cover all possible arrangements

What about BBRRBR?

I think believe my answer is wrong and 4 should be it by laying out the possible arrangements.
_________________

Best Regards,

Paul

SVP
SVP
User avatar
Joined: 30 Oct 2003
Posts: 1798
Location: NewJersey USA
Followers: 4

Kudos [?]: 34 [0], given: 0

GMAT Tests User
 [#permalink] New post 12 May 2004, 21:23
Yeah I agree I missed RBBRRB or BBRRBR

I dont know how to solve this problem using formulas.
Manager
Manager
User avatar
Joined: 07 May 2004
Posts: 184
Location: Ukraine, Russia(part-time)
Followers: 2

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

GMAT Tests User
 [#permalink] New post 12 May 2004, 21:44
anandnk wrote:
Yeah I agree I missed RBBRRB or BBRRBR

I dont know how to solve this problem using formulas.


Anand, as a programmer, you could write some algorithm to solve it. My friend solved this problem for N red and N green (it was given at all-Kazakh programming contest :-)). Kazakhstan is a large country in Central Asia (former Soviet Union).

My answer is:

4.

The method is as follows:

1. Think about combinations where all Bs are actually non-sequential. There is only 1 such comb.

2. Think about combs where only 2 Bs are sequential, but the remaining is not. => 2 combs.

3. Think about combs where all three B are sequential => there is only 1 such comb.

=> 4 is the answer.

The general method for (N greens, N reds) is as follows:

1. with no neighbors = 1.

2. with only 1 pair of 2 neighbors = N-1.

3. with only 2 pairs of 2 neighbors, ... etc.

So, it can be easily done even for N = 4,5.
Intern
Intern
avatar
Joined: 21 Mar 2004
Posts: 11
Location: Evansville, IN
Followers: 0

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

 [#permalink] New post 13 May 2004, 09:35
is 4 official answer?
I am not getting this . any help will be appreciated.
I got 8.
Any circular bracelet with six positions can be imagined as

_ _ _ _ _ _

we are required to sit 3 R balls and 3 B balls in six spaces.

so 2 X 2 X 2 X 1 X 1 X 1 = 8
_________________

Best wishes
Chetan

Manager
Manager
User avatar
Joined: 07 May 2004
Posts: 184
Location: Ukraine, Russia(part-time)
Followers: 2

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

GMAT Tests User
 [#permalink] New post 13 May 2004, 09:49
sunny_god76 wrote:
is 4 official answer?
I am not getting this . any help will be appreciated.
I got 8.
Any circular bracelet with six positions can be imagined as

_ _ _ _ _ _

we are required to sit 3 R balls and 3 B balls in six spaces.

so 2 X 2 X 2 X 1 X 1 X 1 = 8


You got 8 because symmetric allocations were counted TWICE.

RBRBRB == BRBRBR! You did the job twice...

A propos, how did you get 2 X 2 X 2 X 1 X 1 X 1? It should rather be C[3,6] = 6!/(3!*3!) = 24... The fact that there are problems with symmetry makes this problem not so easy. As I've already said, my friend wrote a program to calculate total # of combinations in general case...
  [#permalink] 13 May 2004, 09:49
    Similar topics Author Replies Last post
Similar
Topics:
3 Experts publish their posts in the topic In a jar there are 3 red balls and 2 blue balls. What is the LucyDang 8 31 Jul 2014, 05:47
3 Experts publish their posts in the topic A jar contains 16 marbles, of which 4 are red, 3 are blue, a banksy 5 14 Feb 2011, 16:24
A jar contains 16 marbles, of which 4 are red, 3 are blue, Jcpenny 1 11 Dec 2008, 18:26
A jar contains 16 marbles, of which 4 are red, 3 are blue, mikegao 1 17 Oct 2008, 09:43
In a jar there are 3 red balls and 2 blue balls. What is the shobuj 6 10 Apr 2008, 07:14
Display posts from previous: Sort by

What are the total number of ways, in which 3 red and 3 blue

  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®.