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Homework Help: Probability question

  1. Jan 7, 2009 #1

    The numbers represent the probability that each component works.

    a) What's the probability that the entire system works?
    b) Given that the system works, what's the probability that the component A is not working?

    a) P=.75112, easy
    b) Don't know what to do here....
  2. jcsd
  3. Jan 7, 2009 #2


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    Homework Helper

    Since there is no component A in the diagram, I'd say you can't answer the second question.
    If you were asking this: Given the system works, what is the probability [tex] 1 [/tex]
    is not working, think this way:

    If the system is operating, you know that
    * [tex]3, 4 [/tex] and [tex] 5 [/tex] are all operating
    * [tex] 1 [/tex] is not operating, status of [tex] 2 [/tex] is unimportant

    what can you do with this?
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