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

It is currently 27 Nov 2014, 01:33

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 box has 10 balls. Find how many ways 6 balls can be

  Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
TAGS:
Intern
Intern
avatar
Joined: 05 Jun 2004
Posts: 5
Location: India
Followers: 0

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

A box has 10 balls. Find how many ways 6 balls can be [#permalink] New post 02 May 2005, 06:12
A box has 10 balls. Find how many ways 6 balls can be selected if each ball may be repeated any number of times.
Manager
Manager
User avatar
Joined: 22 Apr 2005
Posts: 129
Location: Los Angeles
Followers: 1

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

 [#permalink] New post 02 May 2005, 10:48
General formula for selection with repetitions.

The number of ways to pick k items out of n with repetitions = kC(n+k-1)

In this case

6C(10+6-1) = 6C15
Intern
Intern
avatar
Joined: 05 Jun 2004
Posts: 5
Location: India
Followers: 0

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

 [#permalink] New post 02 May 2005, 11:06
is there a simpler way of doing this? not able to understand the formula..
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 608
Followers: 3

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

 [#permalink] New post 02 May 2005, 12:04
If all selections are independant from each other I would prefer 10^6
Manager
Manager
User avatar
Joined: 22 Apr 2005
Posts: 129
Location: Los Angeles
Followers: 1

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

 [#permalink] New post 02 May 2005, 12:18
Economiser wrote:
is there a simpler way of doing this? not able to understand the formula..


This is a simple way.
Here is an article for you
http://home.att.net/~numericana/answer/ ... htm#repeat
Senior Manager
Senior Manager
avatar
Joined: 19 Sep 2004
Posts: 371
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 02 May 2005, 21:11
Tyr wrote:
Economiser wrote:
is there a simpler way of doing this? not able to understand the formula..


This is a simple way.
Here is an article for you
http://home.att.net/~numericana/answer/ ... htm#repeat


I find it little difficult to comprehend can someone please exaplain!

Saurabh Malpani
Senior Manager
Senior Manager
avatar
Joined: 19 Sep 2004
Posts: 371
Followers: 1

Kudos [?]: 3 [0], given: 0

 [#permalink] New post 03 May 2005, 03:25
MA wrote:
gmat2me2 wrote:
twixt wrote:
If all selections are independant from each other I would prefer 10^6

Isnt that 6^10??

i also think so.


can you please how ur working.
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 608
Followers: 3

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

 [#permalink] New post 03 May 2005, 04:03
gmat2me2 wrote:
twixt wrote:
If all selections are independant from each other I would prefer 10^6


Isnt that 6^10??


I have to select 6 balls among 10, so first one 10 choices, replacement, second one 10 choices...

That is why I answered 10^6...
Intern
Intern
avatar
Joined: 05 May 2005
Posts: 8
Followers: 0

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

 [#permalink] New post 05 May 2005, 12:58
I think the answer should be:10*9*8*7*6*5,is that right?
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 608
Followers: 3

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

 [#permalink] New post 06 May 2005, 14:09
Maybe an old prob Pro could provide some insight to this one...
VP
VP
avatar
Joined: 26 Apr 2004
Posts: 1226
Location: Taiwan
Followers: 2

Kudos [?]: 117 [0], given: 0

 [#permalink] New post 06 May 2005, 15:27
olivebaby wrote:
I think the answer should be:10*9*8*7*6*5,is that right?


Hi, because being able to repeated, each ball has the same probability of being selected.

Hence repeat 6 times: 10 * 10 *10... = 10^6
Director
Director
avatar
Joined: 18 Feb 2005
Posts: 674
Followers: 1

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

 [#permalink] New post 06 May 2005, 18:38
twixt wrote:
gmat2me2 wrote:
twixt wrote:
If all selections are independant from each other I would prefer 10^6


Isnt that 6^10??


I have to select 6 balls among 10, so first one 10 choices, replacement, second one 10 choices...

That is why I answered 10^6...


Yes Twixt...It is 10^6.....
Director
Director
User avatar
Joined: 31 Aug 2004
Posts: 608
Followers: 3

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

 [#permalink] New post 07 May 2005, 14:32
Thx, During a fraction of second I had the feeling I had lost all my probs concepts !!
  [#permalink] 07 May 2005, 14:32
    Similar topics Author Replies Last post
Similar
Topics:
In how many ways can 5 identical black balls and 7 identical FN 2 22 Oct 2005, 08:49
In how many ways can 4 identical red balls and 5 different gmacvik 5 20 Oct 2005, 18:45
In how many ways can 4 identical red balls and 5 different rchadha 10 05 Oct 2005, 14:47
In how many ways can 5 identical black balls and 7 identical nocilis 5 06 Jan 2005, 09:47
How many ways can 5 identical black balls and 7 identical qhoc0010 2 27 Dec 2004, 13:12
Display posts from previous: Sort by

A box has 10 balls. Find how many ways 6 balls can be

  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®.