Results 1 to 2 of 2

Math Help - Independent Events Question

  1. #1
    Junior Member
    Joined
    Oct 2009
    Posts
    37

    Independent Events Question

    Hello everyone,

    I am having a bit of trouble with finding the answer to this question.
    Students A, B, C each independently on a test. The probability of A getting the right answer is 0.9, for B it is 0.7 and for C it is 0.4.

    If two of them get the right answer, what is the probability that C got their question wrong.

    My logic behind this was finding AB(Not C) = 0.9*0.7*0.6, but apparently this is wrong. The correct answer was 0.7354

    Any insight would be much appreciated. THanks!
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5

    Re: Independent Events Question

    Quote Originally Posted by KelvinScale View Post
    Hello everyone,

    I am having a bit of trouble with finding the answer to this question.
    Students A, B, C each independently on a test. The probability of A getting the right answer is 0.9, for B it is 0.7 and for C it is 0.4.

    If two of them get the right answer, what is the probability that C got their question wrong.

    My logic behind this was finding AB(Not C) = 0.9*0.7*0.6, but apparently this is wrong. The correct answer was 0.7354

    Any insight would be much appreciated. THanks!
    It is conditional probability. You need to divide your answer by the probability that two of them got the right answer .....
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Independent Events
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: November 9th 2010, 03:37 PM
  2. independent events
    Posted in the Advanced Statistics Forum
    Replies: 11
    Last Post: September 28th 2010, 11:46 AM
  3. Independent events
    Posted in the Statistics Forum
    Replies: 1
    Last Post: October 26th 2009, 04:50 AM
  4. independent events
    Posted in the Advanced Statistics Forum
    Replies: 0
    Last Post: September 7th 2009, 07:44 PM
  5. Independent events
    Posted in the Advanced Statistics Forum
    Replies: 1
    Last Post: April 29th 2008, 09:24 AM

Search Tags


/mathhelpforum @mathhelpforum