Results 1 to 2 of 2

Math Help - PLEASE help me guys!!

  1. #1
    Junior Member
    Joined
    Feb 2006
    From
    New Zealand
    Posts
    26

    Unhappy PLEASE help me guys!!

    I'm in desperate need of guidance. I have no idea how to answer this question and it is so frustrating for me because I've spent so long trying to figure it out! Thank you for your help

    In a tournament, two players continue to play each other until one of them wins three games. If the probability that A wins any single game is 0.4 and the probability that B wins it is 0.5, find

    a) the probability the first game is a draw
    b) the probability A wins the first three games
    c) the probability the tournament is just three games long
    d) the probability A wins the first two games, and not the third.
    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 Kiwigirl
    I'm in desperate need of guidance. I have no idea how to answer this question and it is so frustrating for me because I've spent so long trying to figure it out! Thank you for your help

    In a tournament, two players continue to play each other until one of them wins three games. If the probability that A wins any single game is 0.4 and the probability that B wins it is 0.5, find

    a) the probability the first game is a draw
    The probability that the first game is a draw is the probability that
    neither wins, and since A wins with probability 0,4 and B wins with
    probability 0.5, the probability of a draw on any game is 1-0.4-0.5=0.1.

    Therefore the probability that the first game is a draw is the probability
    that any game is a draw and is equal to 0.1

    [
    b) the probability A wins the first three games
    The results of each of the first three games are independent, and the
    probability of A winning in any one of them is 0.4 so the probability of
    A winning the first three games is the product of the probabilities of
    A winning each of them=0.4x0.4x0.4=0.064

    c) the probability the tournament is just three games long
    There are two ways that the tournament can be just three games long;
    A can win the first three games, or B can win the first three games. The
    probabilities of these outcomes are 0.4x0.4x0.4 and 0.5x0.5x0.5
    respectively, and these outcomes are independent the probability of
    one or the other occurring is the sum of their individual probabilities and
    so is:

    0.4x0.4x0.4 + 0.5x0.5x0.5 = 0.189

    d) the probability A wins the first two games, and not the third.
    As the results of each game are independent this is the product of the
    probabilities of the required outcomes of each game. The probability that
    A wins a game is 0.4, the probability that A does not win a game is 1-0.4=0.6.
    So the required probability is 0.4x0.4x0.6=0.096

    RonL
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. how do you guys get to use?
    Posted in the Differential Equations Forum
    Replies: 1
    Last Post: October 5th 2009, 02:54 PM
  2. hello, guys
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: June 24th 2008, 09:19 AM
  3. sorry guys i cant get this one either!
    Posted in the Algebra Forum
    Replies: 2
    Last Post: September 11th 2006, 05:57 PM
  4. one more (sorry guys)
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: May 25th 2006, 09:49 AM
  5. Help Me Guys
    Posted in the Business Math Forum
    Replies: 8
    Last Post: February 24th 2006, 11:04 AM

Search Tags


/mathhelpforum @mathhelpforum