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Conditional Probability

  1. Oct 19, 2009 #1
    An event A has a 70% chance of occurring, an event B has a 40% of occurring and the event (A n B) has a 20% chance of occurring. The events are not unrelated.

    If A does not occur what is the probability of B?

    notation A' means (not A)

    I have tried to use the formula P(B|A') = P(B n A')/P(A')

    However Not sure if that's the right way to go and if A' would be equal to .3.

    Please Help :)
  2. jcsd
  3. Oct 19, 2009 #2


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    Last edited by a moderator: Apr 24, 2017
  4. Oct 19, 2009 #3
    Thanks for the link, I have used one of Baye's laws hopefully that helps give me the right answer.
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