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Homework Help: Probability problem

  1. Jan 29, 2009 #1
    8 balls are in a box. Each ball can be either blue or red. If there are d red balls in the box, calculate the probability p(d) that two randomly selected balls from the ball are both blue. Sketch p(d).

    [tex]p(d) = \frac{_{8-d}C_{2}*_{d}C_{0}}{_{8}C_{2}} = \frac{_{8-d}C_{2}}{14}[/tex]

    Is this correct? Is there a better way to write it so that I can sketch p(d)?
     
    Last edited: Jan 29, 2009
  2. jcsd
  3. Jan 29, 2009 #2

    tiny-tim

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    Hi kasse! :smile:

    P(1st = blue) times P(2nd = blue | 1st = blue) :wink:
     
  4. Jan 29, 2009 #3
    Of course!
     
    Last edited: Jan 29, 2009
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