Results 1 to 3 of 3

Math Help - Help with probabilities and combined events.

  1. #1
    Newbie
    Joined
    Jul 2011
    Posts
    4

    Help with probabilities and combined events.

    I am studying for the GMAT, but in the midst of taking notes have run across some instructions I just cannot figure out. I have taken Stats, so this will be a refresher, but it seems I forgot tons of stuff I learned in the class.

    Here is the instructions given.

    For the number cube, if E is the event that the outcome is an odd number, {1, 3, 5}, and F is the event that the outcome is a prime number, {2, 3, 5}, then P(E and F) = P({3, 5}) = 2/6.

    Okay, I get hitched where the equatiion includes P({3, 5}). Why is there a 5 in there? It seems that there are 3 odd number, {1, 3, 5}, and 3 prime number, {2, 3, 5}, so why wouldn't the equation read, P({3, 3})?

    Thanks for the help!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Aug 2006
    Posts
    18,711
    Thanks
    1640
    Awards
    1

    Re: Help with probabilities and combined events.

    Quote Originally Posted by Stoneface View Post
    For the number cube, if E is the event that the outcome is an odd number, {1, 3, 5}, and F is the event that the outcome is a prime number, {2, 3, 5}, then P(E and F) = P({3, 5}) = 2/6. Why is there a 5 in there? It seems that there are 3 odd number, {1, 3, 5}, and 3 prime number, {2, 3, 5}, so why wouldn't the equation read, P({3, 3})?
    AND is just intersection.
    E=\{1,3,5\}~\&~F=\{2,3,5\} so E\cap F=\{3,5\}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2011
    Posts
    4

    Re: Help with probabilities and combined events.

    So, it is just an intersection. Thanks!
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 3
    Last Post: January 7th 2012, 10:23 AM
  2. Replies: 3
    Last Post: September 22nd 2011, 09:46 AM
  3. Approximate joint probabilities using marginal probabilities
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: June 23rd 2011, 04:04 AM
  4. Finding probabilities of two events.
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: May 31st 2010, 11:21 AM
  5. combined events and conditional probability
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 24th 2010, 01:18 AM

Search Tags


/mathhelpforum @mathhelpforum