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permutation and combination problem
by kumar swambhu - Sunday, 2 August 2009, 03:13 PM
 

there are 5 blue socks,4 red socks and 3 green one.in how many ways i can select 4 socks?

  

Re: permutation and combination problem
by niramay nothing - Monday, 3 August 2009, 04:17 PM
  13..
Re: permutation and combination problem
by Ravish Shetty - Monday, 3 August 2009, 08:11 PM
  can you explain how do you get to the answer 13?
Re: permutation and combination problem
by niramay nothing - Wednesday, 5 August 2009, 11:17 AM
  I did like this:

4B
3B, 1R
3B, 1G
2B, 1R, 1G
2B, 2G
2B, 2R
1B, 3R
1B, 2R, G
1B, 1R, 2G
4R
3R,G
2R, 2G
1R, 3G
 
please somebody correct me and also come up with an efficient method
thanks
Re: permutation and combination problem
by varun sood - Monday, 17 August 2009, 01:03 PM
  12c4
Re: permutation and combination problem
by ashish duhan - Friday, 21 August 2009, 06:12 PM
  can you please explain it.
Re: permutation and combination problem
by harsh the great - Sunday, 23 August 2009, 06:11 AM
  We have total 12 socks.
We need to select 3 socks now.. we dont care about color.
So answer should be :

12C4= 12*11*10*9/4*3*2
Re: permutation and combination problem
by gopal botadra - Friday, 14 October 2011, 10:26 AM
  c(12,4)
=12*11*10*9/4*3*2
=495
Re: permutation and combination problem
by TG Team - Friday, 14 October 2011, 01:51 PM
 

Just reframe the question as finding number of whole number solution of equation:

B + R + G = 4

where B, R, G represents the boxes which contain blue, red and green socks respectively such that B ≤ 5, R ≤ 4 and G ≤ 3.

Clearly, required number of solutions are C(4 + 3 - 1, 3 - 1) - 1 = C(6, 2) - 1 = 15 - 1 = 14. smile

Kamal Lohia

Re: permutation and combination problem
by Muhammad Saif Anwer - Friday, 21 October 2011, 06:06 AM
  C(4+ 3 - 1, 3 - 1) - 1????? How did u get dat?
Re: permutation and combination problem
by TG Team - Friday, 21 October 2011, 11:35 AM
 

See this:

cat
Kamal Lohia

Re: permutation and combination problem
by Suhani Shrivastava - Wednesday, 15 February 2012, 10:33 AM
  495
Re: permutation and combination problem
by TG Team - Thursday, 16 February 2012, 04:13 PM
 

Suhani smile

It'll be very nice if you can explain your answer also.

Kamal Lohia

Re: permutation and combination problem
by dhwani bhatt - Sunday, 4 March 2012, 01:43 PM
  But why did you subtracted 1 ?
Re: permutation and combination problem
by ishant goel - Wednesday, 7 March 2012, 02:14 AM
  Because G= 3 and hence one case (i.e. ||GGGG ) is not possible. smile