Results 1 to 3 of 3

Math Help - Difficult probability problem

  1. #1
    Newbie
    Joined
    Sep 2008
    Posts
    18

    Difficult probability problem

    A large white cube is painted red, and then cut into 27 identical smaller cubes. These smaller cubes are shuffled randomly. A blind man (who also cannot feel the paint) reassembles the small cubes into a large one. What is the probability that the outside if this large cube is completely red?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    May 2010
    Posts
    1,027
    Thanks
    28

    Re: Difficult probability problem

    there are 4 types of subcube:

    those with no sides painted (1)
    those with 1 sides painted (6)
    those with 2 sides painted (12)
    those with 3 sides painted (8)

    Any shuffling of these subcubes within their own group will keep the cube exterior completely red, so there are 1!6!12!8! possible solutions. You should allow for orientations but i think this has no effect on this part of the calc (i think that for any given position, only 1 orientation is valid).

    Step two: find the total number of outcomes (including orientations) and divide one by the other.

    PS: I should warn you i dont have the best track record at combinatronics problems so i might have got that spectacularly wrong
    Last edited by SpringFan25; August 29th 2011 at 10:28 AM.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6

    Re: Difficult probability problem

    Quote Originally Posted by SpringFan25 View Post
    PS: I should warn you i dont have the best track record at combinatronics problems so i might have got that spectacularly wrong
    I hope you're better at combinatorics
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Difficult probability question
    Posted in the Statistics Forum
    Replies: 2
    Last Post: February 1st 2011, 05:40 AM
  2. difficult problem
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 30th 2010, 03:41 AM
  3. Replies: 16
    Last Post: October 9th 2010, 01:43 AM
  4. Probability Question-Not too difficult
    Posted in the Statistics Forum
    Replies: 7
    Last Post: March 9th 2010, 09:22 AM
  5. Difficult probability quesiton please help
    Posted in the Advanced Statistics Forum
    Replies: 2
    Last Post: December 10th 2007, 12:42 PM

Search Tags


/mathhelpforum @mathhelpforum