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Homework Help: What is the probability that the first toss was the tail?

  1. Jan 10, 2009 #1
    1. The problem statement, all variables and given/known data
    A coin is tossed 3 times and you note that the coin lands heads exactly twice. What is the probability that the first toss was the tail?


    3. The attempt at a solution

    I've solved the problem manually not using notation.


    So I want to try to solve with notation?

    Thanks
     
  2. jcsd
  3. Jan 10, 2009 #2

    rock.freak667

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    Homework Helper

    Re: Probability

    I am not familiar with the notation you speak of, can you give me an example of what you're asking for?
     
  4. Jan 10, 2009 #3
    Re: Probability

    p(the coin landed tail)=.5
     
  5. Jan 10, 2009 #4
    Re: Probability

    Without using nCr
    But Conditional Prbability
     
  6. Jan 10, 2009 #5
    Re: Probability

    Well what answer did you get? :)
     
  7. Jan 10, 2009 #6
    Re: Probability

    i also learning probability and just to ask those who have completed this, is the answer 1/6 ?
     
  8. Jan 10, 2009 #7

    Delphi51

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    Re: Probability

    Tricky! I'm thinking of a manual solution like this:
    The possible outcomes are HHT, HTH, THH.
    BUT I'm wondering if I need to distinguish between the two H's so it is
    HhT, hHT,HTh,hTH,THh,ThH
     
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