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Math Help - 2 probability questions

  1. #1
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    2 probability questions

    a lot of Thank you ...
    Attached Thumbnails Attached Thumbnails 2 probability questions-image079.jpg   2 probability questions-image080.jpg  
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  2. #2
    ddt
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    Quote Originally Posted by Narek View Post
    a lot of Thank you ...
    As to the first: look at the probabilities of the complements:
    P(U\E) = ???
    P(U\F) = ???
    and then look at P(U\(E n F)).

    (where U is the "universe", i.e., all events).

    As to the second: does it really matter which birthday person1 has? So, say it's January 13. Then look at the birthday of person2.
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  3. #3
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    Refer to the link below, you will be able to solve the 2nd problem.

    Birthday problem - Wikipedia, the free encyclopedia
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  4. #4
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    cant solve the first one!!

    I dont get the point .... can you solve it?
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  5. #5
    ddt
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    Quote Originally Posted by Narek View Post
    I dont get the point .... can you solve it?
    Try first: what's the probability that E does not occur, i.e. P(U \ E) ?
    Likewise, the probability that F does not occur?

    What's the sum of those?

    What has that to do with the probability that (E n F) does not occur?
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  6. #6
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    answer to birthday problem

    we dont know what day is for the first person, so we consider it as 1st january. and now we say, the probability of the second person having the same birthday is :

    P= 1 / 366

    __________________________________________________ ________

    is this True???? thank you
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  7. #7
    ddt
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    Quote Originally Posted by Narek View Post
    we dont know what day is for the first person, so we consider it as 1st january. and now we say, the probability of the second person having the same birthday is :

    P= 1 / 366

    __________________________________________________ ________

    is this True???? thank you
    Yes, that's correct.
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  8. #8
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    for the first one, no matter how hard I try, I dont understand the concept ... I need to see the solution, please
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  9. #9
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    any suggestion???

    any suggestion??? any guide?
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  10. #10
    Grand Panjandrum
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    Quote Originally Posted by Narek View Post
    any suggestion??? any guide?
    P(E\cup F)=P(E)+P(F)-P(E \cap F) \le 1

    CB
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