Results 1 to 1 of 1

Math Help - Letters and envelopes

  1. #1
    Newbie
    Joined
    Mar 2012
    From
    Canberra
    Posts
    2

    Question Letters and envelopes

    Suppose that you have 20 different letters and 10 distinctly addressed envelopes. The
    20 letters consist of 10 pairs, where each pair belongs inside one of the 10 envelopes.
    Suppose that you place the 20 letters inside the 10 envelopes, two per envelope, but at random.

    What is the probability that exactly 3 of the 10 envelopes will contain both of the
    letters which they should contain?

    Please help, I will remember you forever
    Last edited by nhatdisk; March 27th 2012 at 06:52 AM.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Putting letters into envelopes
    Posted in the Statistics Forum
    Replies: 7
    Last Post: July 11th 2010, 01:15 PM
  2. Envelopes and Paychecks Problems
    Posted in the Advanced Statistics Forum
    Replies: 8
    Last Post: June 6th 2010, 11:17 AM
  3. Arrangement of letters
    Posted in the Discrete Math Forum
    Replies: 0
    Last Post: October 18th 2009, 12:30 PM
  4. A two-envelopes puzzle (probability)
    Posted in the Statistics Forum
    Replies: 1
    Last Post: September 2nd 2008, 10:34 AM
  5. The two envelopes problem
    Posted in the Advanced Statistics Forum
    Replies: 15
    Last Post: November 24th 2006, 12:00 AM

Search Tags


/mathhelpforum @mathhelpforum