Results 1 to 3 of 3

Math Help - Probability

  1. #1
    Newbie
    Joined
    Apr 2009
    Posts
    16

    Probability

    Solvbe this:-

    There are six boys and girls who sits in one row. Find the probability that no two boy sits together.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Mar 2009
    Posts
    52
    Six boys can be placed in 7 places in 7 C 1 ways.

    Probability of no 2 boys sitting together is 2/7.

    please correct me if I am wrong.

    Thanks,
    Ashish
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Grandad's Avatar
    Joined
    Dec 2008
    From
    South Coast of England
    Posts
    2,570
    Thanks
    1

    Probability

    Hello vivek_master146
    Quote Originally Posted by vivek_master146 View Post
    Solvbe this:-

    There are six boys and girls who sits in one row. Find the probability that no two boy sits together.
    Do you mean six boys and six girls? It is vital that you write down questions like this exactly as they were first written!

    If there are six boys and six girls, then we can arrange them in a row in 12! ways.

    If no two boys sit together, then either:

    • the boys sit in places 1, 3, ..., 11 (and the girls in places 2, 4, ..., 12); or


    • the boys sit in places 2, 4, ..., 12 (and the girls in places 1, 3, ..., 11)

    Each of these arrangements can be done in 6! x 6! different ways. So the probability that one of these occurs is

    \frac{2\times 6!\times 6!}{12!}= \frac{1}{462}

    Grandad
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 10
    Last Post: January 21st 2011, 12:47 PM
  2. Replies: 3
    Last Post: May 29th 2010, 08:29 AM
  3. fundamental in probability & convergence with probability 1
    Posted in the Advanced Statistics Forum
    Replies: 3
    Last Post: February 23rd 2010, 10:58 AM
  4. Replies: 1
    Last Post: February 18th 2010, 02:54 AM
  5. Replies: 3
    Last Post: December 15th 2009, 07:30 AM

Search Tags


/mathhelpforum @mathhelpforum