1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

4th Combinatorial problem

  1. Jul 18, 2007 #1
    1. The problem statement, all variables and given/known data
    A group comprising 6 peoiple is sitting around a table. Find the probability that two particular people are sitting next to each other.

    2. Relevant equations

    3. The attempt at a solution

    4!2!/5!=2/5 because total number of possibities is 5!. If 2 people are to be next to each other than there are 5 groups so 4! choices with each choice, one can swap the group of two. So times by 2!.

    BUt the answers suggested 1/5
  2. jcsd
  3. Jul 18, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper

    Some really dubious 'answers' are being suggested to you. The answer is clearly 2/5. Pick one of the particular people. There are 2 people sitting next to him and 3 not. The odds the other particular person is in the former group is 2/5.
    Last edited: Jul 18, 2007
  4. Jul 18, 2007 #3
    That is a nice way of doing it.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: 4th Combinatorial problem
  1. Combinatory problem. (Replies: 17)