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    If I took a 10 digit, 3 letter combination lock where the combination could include 1 to 13 digits, would the number of possible combinations be
    13C1 + 13C2 ..... + 13C13
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    (Original post by jsmith6131)
    If I took a 10 digit, 3 letter combination lock where the combination could include 1 to 13 digits, would the number of possible combinations be
    13C1 + 13C2 ..... + 13C13
    I don't think so.
    Order's important in a combination lock - it's actually a permutation lock but hey ho:
    I'm not 100% but the numbers and letters are independent of each other,
    So there are  10^{10} \times 26^3 ways of making a unique code, assuming you use all the units. Which is considerably larger than what you proposed at around 1.7576 \times 10^{14}
    If you use fewer units as the code, it becomes more and more complicated
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    (Original post by joostan)
    I don't think so.
    Order's important in a combination lock - it's actually a permutation lock but hey ho:
    I'm not 100% but the numbers and letters are independent of each other,
    So there are  10^{10} \times 26^3 ways of making a unique code, assuming you use all the units. Which is considerably larger than what you proposed at around 1.7576 \times 10^{14}
    If you use fewer units as the code, it becomes more and more complicated
    On the lock I am referring to once the order in which the keys are pressed is NOT relevant!!
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    (Original post by jsmith6131)
    On the lock I am referring to once the order in which the keys are pressed is NOT relevant!!
    There's still the possibility of choosing from 26 possible letters and the 10 digits etc.
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    (Original post by joostan)
    There's still the possibility of choosing from 26 possible letters and the 10 digits etc.
    no its a 0-9 and X,Y,Z combination lock

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    (Original post by jsmith6131)
    no its a 0-9 and X,Y,Z combination lock

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    Oh. Ok, if the order doesn't matter, are you allowed to hit the same button twice?
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    (Original post by joostan)
    Oh. Ok, if the order doesn't matter, are you allowed to hit the same button twice?
    no....i.e: if you do it makes absolutely no difference AND the code X739 = 973X.... it makes NO difference which ORDER you push the buttons
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    (Original post by jsmith6131)
    no....i.e: if you do it makes absolutely no difference AND the code X739 = 973X.... it makes NO difference which ORDER you push the buttons
    In which case, I believe that you were right in your initial post and I've been wasting your time
 
 
 
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