Results 1 to 2 of 2

Math Help - Probability question, The birthday problem

  1. #1
    Newbie
    Joined
    Mar 2010
    Posts
    8

    Probability question, The birthday problem

    Two people enter a room and their birthdays (ignoring years) are recorded.
    (a) Identify the nature of simple events in S.

    (b) What is the probability that the two people have a specific pair of birth dates?

    (c) Identify the simple events in event A:Both people have the same birthday.

    (d)Find P(A)

    (e) Find P(A^c)

    Any help will be greatly appreciated,
    cheers RaVS!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by RaVS View Post
    Two people enter a room and their birthdays (ignoring years) are recorded.
    (a) Identify the nature of simple events in S.

    (b) What is the probability that the two people have a specific pair of birth dates?
    (a) The sample space is the set of all ordered pairs of birth days (that is if the two people are distinguishable) or of all sets of two birth days (if the people are not distinguishable the order of the dates is not relevant)

    (b) Suppose the people are distinguishable, the first can gave any of 365 birthdays, and independently the second can have any of the 365 birthdays. All of these are equally likely so the number of possible pairs of birthdays is 365 \times 365, and as these are all equally likely the probability of any one is 1/365^2.

    CB
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Question on the Birthday Problem
    Posted in the Statistics Forum
    Replies: 3
    Last Post: November 30th 2011, 03:37 PM
  2. Probability of having the same birthday
    Posted in the Statistics Forum
    Replies: 12
    Last Post: February 18th 2010, 03:14 PM
  3. Birthday probability
    Posted in the Statistics Forum
    Replies: 1
    Last Post: November 12th 2009, 09:47 PM
  4. Probability birthday same day
    Posted in the Statistics Forum
    Replies: 7
    Last Post: February 17th 2008, 10:52 PM
  5. The Birthday Problem (another probability question)
    Posted in the Advanced Statistics Forum
    Replies: 4
    Last Post: April 29th 2007, 01:11 AM

Search Tags


/mathhelpforum @mathhelpforum