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  1. #1
    Silver Lounger GARYPSWANSON's Avatar
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    3 Digit Combination

    My daughter has this homework question and she doesn't believe her dear old dad....


    Question: How many different 3-digit area codes can be created if no digit can be repeated?
    Regards,

    Gary
    (It's been a while!)

  2. #2
    Plutonium Lounger
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    Re: 3 Digit Combination

    How much extraneous information has to be taken for granted? For example, in the country where I live, 0 (zero) can be part of an area code.

  3. #3
    WS Lounge VIP sdckapr's Avatar
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    Re: 3 Digit Combination

    <P ID="edit" class=small>(Edited by sdckapr on 07-Feb-05 21:14. Added PS and hid results)</P>Assuming that the first can be zero:

    <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">10*9*8= 720</span hide>

    Steve
    PS. If the first can not be zero then
    <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">720 - 1*9*8 = 648</span hide>

  4. #4
    Platinum Lounger
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    Re: 3 Digit Combination

    Gary

    ...was her dear old dad correct...? <img src=/S/evilgrin.gif border=0 alt=evilgrin width=15 height=15>
    Jerry

  5. #5
    Gold Lounger
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    Re: 3 Digit Combination

    Steve,

    It seems as if you edited your answer yesterday!!!!!
    How did you know that Gary was going to ask the question today!! And if you knew, why did you not post the correct answer straight off.?? <img src=/S/scratch.gif border=0 alt=scratch width=25 height=29>
    Regards,
    Rudi

  6. #6
    Platinum Lounger
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    Re: 3 Digit Combination

    Don't forget that Steve is a WMVP. They're expected, among other things, to be able to provide answers to questions before they're asked. <img src=/S/wink.gif border=0 alt=wink width=15 height=15>

    Alan

  7. #7
    WS Lounge VIP sdckapr's Avatar
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    Re: 3 Digit Combination

    <img src=/S/confused.gif border=0 alt=confused width=15 height=20>

    I answered it and edited it yesterday (in the span of about 2 mins). The question was asked yesterday as far as I could tell, but perhaps Hans and I both used our "WMVP" powers if it were posted today...

    Steve

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