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

 It is currently 25 May 2016, 12:04

### 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

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

# Events & Promotions

###### Events & Promotions in June
Open Detailed Calendar

# How many ways are there to create four teams of three from a

Author Message
Director
Joined: 23 May 2008
Posts: 838
Followers: 3

Kudos [?]: 53 [0], given: 0

How many ways are there to create four teams of three from a [#permalink]

### Show Tags

05 Aug 2008, 22:30
This topic is locked. If you want to discuss this question please re-post it in the respective forum.

How many ways are there to create four teams of three from a group of twelve students?

Director
Joined: 10 Sep 2007
Posts: 947
Followers: 8

Kudos [?]: 248 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

05 Aug 2008, 22:55
12c3*9c3*6c3*3c3/4!
Senior Manager
Joined: 23 May 2006
Posts: 326
Followers: 2

Kudos [?]: 200 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

05 Aug 2008, 23:01
Agree with Abhijit
Director
Joined: 23 May 2008
Posts: 838
Followers: 3

Kudos [?]: 53 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

05 Aug 2008, 23:04
can you supply a brief explanation?
Director
Joined: 23 May 2008
Posts: 838
Followers: 3

Kudos [?]: 53 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

05 Aug 2008, 23:09
never mind..i get it, but i'm looking for a more intuitive way to do combo problems.
Manager
Joined: 15 Jul 2008
Posts: 207
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 05:09
abhijit_sen wrote:
12c3*9c3*6c3*3c3/4!

could you explain the division by 4!

Thanks..
SVP
Joined: 30 Apr 2008
Posts: 1888
Location: Oklahoma City
Schools: Hard Knocks
Followers: 39

Kudos [?]: 524 [0], given: 32

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 07:07
Once you get the 4 teams created with 3 members on each team, you do not want to count the order of the teams as different.

Name the teams: Team A, Team B, Team C, Team D.

A-B-C-D is the same as B-A-C-D

Because there are 4 teams, divide by 4! (24)
bhushangiri wrote:
abhijit_sen wrote:
12c3*9c3*6c3*3c3/4!

could you explain the division by 4!

Thanks..

_________________

------------------------------------
J Allen Morris
**I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a.

GMAT Club Premium Membership - big benefits and savings

Manager
Joined: 15 Jul 2008
Posts: 207
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 07:19
jallenmorris wrote:
Once you get the 4 teams created with 3 members on each team, you do not want to count the order of the teams as different.

Name the teams: Team A, Team B, Team C, Team D.

A-B-C-D is the same as B-A-C-D

Because there are 4 teams, divide by 4! (24)

But what i am still not clear about is, how does the expression 12C3*9C3*6C3*3C3 count the order..
Manager
Joined: 15 Jul 2008
Posts: 207
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 07:22
think .. i got it..

12C3*9C3*.... is akin to doing n*(n-1)*(n-2) which takes into account an order.... and in these cases you divide by appropriate x! when you want to disregard the order or when there are x of same type. right ?

Thanks
Intern
Joined: 03 Sep 2007
Posts: 13
Followers: 0

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

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 07:29
I'm still slightly confused. What does the c stand for?
Manager
Joined: 15 Jul 2008
Posts: 207
Followers: 3

Kudos [?]: 42 [0], given: 0

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 07:33
rahulm wrote:
I'm still slightly confused. What does the c stand for?

combination. you will see sometimes see p which stands for permutation.
Manager
Joined: 27 Mar 2008
Posts: 69
Followers: 1

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

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 08:29
No. of ways to form 1st team: 12*11*10= 1320
No. of ways to form 2nd team: 9*8*7=504
No. of ways to form 3rd team: 6*5*4=120
No. of ways to form 4th team: 3*2*1=6

therefore total: 1950 (ans)

Whats the OA/OE?
SVP
Joined: 07 Nov 2007
Posts: 1820
Location: New York
Followers: 30

Kudos [?]: 702 [0], given: 5

Re: combination from veritas prep [#permalink]

### Show Tags

06 Aug 2008, 08:56
dishant007 wrote:
No. of ways to form 1st team: 12*11*10= 1320
No. of ways to form 2nd team: 9*8*7=504
No. of ways to form 3rd team: 6*5*4=120
No. of ways to form 4th team: 3*2*1=6

therefore total: 1950 (ans)

Whats the OA/OE?

this is incorrect you are taking permutaitons. Here order is not important.
No. of ways to form 1st team: 12*11*10= 1320
it should be 12c3

take another example if there 3 persons and need to form team of 3 person. how many ways you can do it.
PEROSNS A B C
only one team can be formed .. ABC
here order doesn't matter ABC=BCA=CBA=..
3C3

If question asks how do you arange 3 persons in 3 seats.
then 3!
_________________

Smiling wins more friends than frowning

Re: combination from veritas prep   [#permalink] 06 Aug 2008, 08:56
Display posts from previous: Sort by