facing a problem... Need solution.

For discussing Olympiad Level Combinatorics problems
Shahriar tanvir
Posts:8
Joined:Thu Mar 08, 2012 6:51 pm
facing a problem... Need solution.

Unread post by Shahriar tanvir » Thu Mar 08, 2012 7:39 pm

A bacteria has 8 flazela. 3 of them are green, 2 of them are blue, 2 of them are white & the last one is pink. What is the probability of blue flazela not getting placed beside the white ones.......

User avatar
rakeen
Posts:384
Joined:Thu Dec 09, 2010 5:21 pm
Location:Dhaka

Re: facing a problem... Need solution.

Unread post by rakeen » Wed Nov 07, 2012 1:42 am

i guess you should give the solution :P
r@k€€/|/

User avatar
nafistiham
Posts:829
Joined:Mon Oct 17, 2011 3:56 pm
Location:24.758613,90.400161
Contact:

Re: facing a problem... Need solution.

Unread post by nafistiham » Sun Nov 11, 2012 11:02 am

Shahriar tanvir wrote:A bacteria has 8 flazela. 3 of them are green, 2 of them are blue, 2 of them are white & the last one is pink. What is the probability of blue flazela not getting placed beside the white ones.......
Well, it seems like a 'pearls in the necklace' type problem. But, bacteria is not a 2d object that has flagella just in a circle. it has them all around it. so, how can you define being 'placed beside white ones' ?
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.
Introduction:
Nafis Tiham
CSE Dept. SUST -HSC 14'
http://www.facebook.com/nafistiham
nafistiham@gmail

User avatar
SANZEED
Posts:550
Joined:Wed Dec 28, 2011 6:45 pm
Location:Mymensingh, Bangladesh

Re: facing a problem... Need solution.

Unread post by SANZEED » Sun Nov 11, 2012 10:06 pm

nafistiham wrote:
Shahriar tanvir wrote:A bacteria has 8 flazela. 3 of them are green, 2 of them are blue, 2 of them are white & the last one is pink. What is the probability of blue flazela not getting placed beside the white ones.......
Well, it seems like a 'pearls in the necklace' type problem. But, bacteria is not a 2d object that has flagella just in a circle. it has them all around it. so, how can you define being 'placed beside white ones' ?
I think in this case,we have to consider a $2D$ bacteria,or else a bacteria drawn on a sheet of paper. ;)
$\color{blue}{\textit{To}} \color{red}{\textit{ problems }} \color{blue}{\textit{I am encountering with-}} \color{green}{\textit{AVADA KEDAVRA!}}$

User avatar
nafistiham
Posts:829
Joined:Mon Oct 17, 2011 3:56 pm
Location:24.758613,90.400161
Contact:

Re: facing a problem... Need solution.

Unread post by nafistiham » Sun Nov 11, 2012 11:40 pm

well, so I am describing my solution defining ' blue flazela not getting placed beside the white ones'
as, if any blue and white flagella is staying alongside, we discount it

suppose there is no condition, so, number of all the available permutation is
\[\frac{7!}{3!\cdot 2!\cdot2! }\]
and we can discount
\[\frac{2!\cdot 6!}{3!}\]
so the probability will be
\[\frac{\frac{7!}{3!\cdot 2!\cdot2! }-\frac{2!\cdot 6!}{3!}}{\frac{7!}{3!\cdot 2!\cdot2! }}\]
\[\sum_{k=0}^{n-1}e^{\frac{2 \pi i k}{n}}=0\]
Using $L^AT_EX$ and following the rules of the forum are very easy but really important, too.Please co-operate.
Introduction:
Nafis Tiham
CSE Dept. SUST -HSC 14'
http://www.facebook.com/nafistiham
nafistiham@gmail

Post Reply