Results 1 to 2 of 2

Math Help - Question about probability ?

  1. #1
    Newbie
    Joined
    Dec 2010
    From
    United Kingdom
    Posts
    15

    Question about probability ?

    One evening a drunken hotel clerk tried to hang 11 keys on their 11 hooks, but only managed to hang them independently and at random. there was no limit to the number of keys which could be hung on any hook. Find the probability of:
    a) At least 1 key was hung on its own hook
    b) At least 1 key was hung on the wrong hook
    how did you get there ?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Newbie
    Joined
    Jan 2011
    Posts
    15
    Quote Originally Posted by abrahamtim View Post
    One evening a drunken hotel clerk tried to hang 11 keys on their 11 hooks, but only managed to hang them independently and at random. there was no limit to the number of keys which could be hung on any hook. Find the probability of:
    a) At least 1 key was hung on its own hook
    b) At least 1 key was hung on the wrong hook
    how did you get there ?
    At least 1 key was hung on its own hook= 1-(no key was hung on its own hook)=1-(10/11)^11
    b) At least 1 key was hung on the wrong hook=1-(no key was hung on the wrong hook)=1-(all keys were hung on the right hook)=1-(1/11)^11
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 5
    Last Post: February 10th 2013, 02:11 PM
  2. probability question
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: November 20th 2010, 09:30 AM
  3. Probability question involving (A given B type question )
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: November 9th 2009, 09:08 AM
  4. Probability question need help
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 27th 2009, 07:17 PM
  5. A probability question and an Expectations question
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: January 29th 2006, 06:13 PM

Search Tags


/mathhelpforum @mathhelpforum