Riddles/Math/Logic

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  1. #16
    moi
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    why not
    hello, internet!

  2. #17
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    As soon as you take some dirt out it's a whole hole

  3. #18
    Registered User Aran's Avatar
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    yup, that's the right answer ken and drive.

  4. #19
    . Driveway's Avatar
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    See, I'm not completly stupid.
    Riddle: (easy one)
    The Pope has it but he does not use it. Your father has it but your mother uses it. Nuns do not need it. Your lady friend's husband has it and she uses it. What is it?

  5. #20
    moi
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    Originally posted by Driveway
    See, I'm not completly stupid.
    Riddle: (easy one)
    The Pope has it but he does not use it. Your father has it but your mother uses it. Nuns do not need it. Your lady friend's husband has it and she uses it. What is it?
    a penis.
    hello, internet!

  6. #21
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    Better than the real answer, but no

  7. #22
    BMJ
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    My riddle: (I gave up on the other one)


    A hunter sets out from camp at 4 o'clock in the morning with a compass. According to the compass, he travels due south for 4 hours. At that time he sees a bear and kills it (he is a hunter after all). He drags the bear with him for 4 hours due east, and he takes a quick break. Then he drags the bear due north for 4 hours at which time he arrives back at his camp where he decides he doesn't want the bear after all, packs his SUV and leaves.

    So what color was the bear that he killed?

  8. #23
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    white

  9. #24
    ¡Amo fútbol!
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    What has been done by every male, except for one? Normally does it with many, but can do it by herself. Is world-renowned for her infinite skill and great noise. And gives many great pleasure.

    P.S. You'll probably never get this.

  10. #25
    Registered User rahaydenuk's Avatar
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    A maths one...

    Well here's a maths one (quite easy):

    By considering the series,

    1 + t + t^2 + t^3 + ... + t^n

    sum the series,

    1 + 2t + 3t^2 + 4t^3 + ... + nt^(n-1)

    for t not = 1, where a^b denotes a raised to the bth power.

    Have fun!
    Richard Hayden. (rahaydenuk@yahoo.co.uk)
    Webmaster: http://www.dx-dev.com
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    PGP: 0x779D0625

  11. #26
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    Good problem!
    I think it's

    (n * t^(n+1) - (n + 1) * t^n + 1) / (t-1)^2
    I even sort of proved it.

  12. #27
    Registered User rahaydenuk's Avatar
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    Originally posted by Nick
    Good problem!
    I think it's

    (n * t^(n+1) - (n + 1) * t^n + 1) / (t-1)^2
    I even sort of proved it.
    Yeah that's correct, but where's the proof??
    Richard Hayden. (rahaydenuk@yahoo.co.uk)
    Webmaster: http://www.dx-dev.com
    DXOS (My Operating System): http://www.dx-dev.com/dxos

    PGP: 0x779D0625

  13. #28
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    This is how I found the answer

    Code:
    1 + t  + t^2 + t^3 + ...  + t^n
       + t  + t^2 + t^3 + .... + t^n
              + t^2 + t^3 + ...  + t^n
                        + t^3 + ...  + t^n
                            ....
                                           + t^n
    This I proved this was equal to
    1 + 2t + 3t^2 + 4t^3 + ... + nt^(n-1)

    After that I solved the sums and then used induction
    to prove/check the final answer.

  14. #29
    Registered User rahaydenuk's Avatar
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    Originally posted by Nick
    This is how I found the answer

    Code:
    1 + t  + t^2 + t^3 + ...  + t^n
       + t  + t^2 + t^3 + .... + t^n
              + t^2 + t^3 + ...  + t^n
                        + t^3 + ...  + t^n
                            ....
                                           + t^n
    This I proved this was equal to
    1 + 2t + 3t^2 + 4t^3 + ... + nt^(n-1)

    After that I solved the sums and then used induction
    to prove/check the final answer.
    I see, well done, but I have a much shorter proof, using 1 + t + t^2 + t^3 + ... + t^n. Can you/anyone else find it?

    You'll kick yourselves...

    Good Luck!
    Richard Hayden. (rahaydenuk@yahoo.co.uk)
    Webmaster: http://www.dx-dev.com
    DXOS (My Operating System): http://www.dx-dev.com/dxos

    PGP: 0x779D0625

  15. #30
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    I noticed that derivative
    of 1 + t + t^2 + t^3 + ... + t^n
    is the 0 + 1 + 2t + 3t^2 +... + nt^(n-1)
    I'm sure you could give a prove or solve it some how
    using this?

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