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  4. How do I generate a number divisable by 5, and check it?

How do I generate a number divisable by 5, and check it?

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  • L Luc Pattyn

    BS.

    zero times x equals zero, no matter what (finite) value x has.

    so (the right side's) zero is divisible by x, and the result is (the left side's) zero. If I hold 10 pies, 5 bacon sandwiches, and zero glasses of milk, I have no problem distributing them evenly to 5 people. Next you'll state you could also redefine 5, so it no longer divides itself. :)

    Luc Pattyn [My Articles] Nil Volentibus Arduum

    OriginalGriffO Offline
    OriginalGriffO Offline
    OriginalGriff
    wrote on last edited by
    #16

    Luc Pattyn wrote:

    Next you'll state you could also redefine 5, so it no longer divides itself.

    It doesn't. There are only four bacon sandwiches left... :laugh:

    Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together. Manfred R. Bihy: "Looks as if OP is learning resistant."

    "I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
    "Common sense is so rare these days, it should be classified as a super power" - Random T-shirt

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    • L Luc Pattyn

      BS.

      zero times x equals zero, no matter what (finite) value x has.

      so (the right side's) zero is divisible by x, and the result is (the left side's) zero. If I hold 10 pies, 5 bacon sandwiches, and zero glasses of milk, I have no problem distributing them evenly to 5 people. Next you'll state you could also redefine 5, so it no longer divides itself. :)

      Luc Pattyn [My Articles] Nil Volentibus Arduum

      D Offline
      D Offline
      David1987
      wrote on last edited by
      #17

      Nope. You seem to think that that is the only definition of divisibility. I did not personally redefine anything. There is no natural number n such that 0/x=n so no x evenly divides 0. If you use the definition with integers instead of natural numbers, everything divides zero. Also, the prime factorization of zero is empty.

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      • S stephen darling

        Hi. First, how would I create a random number, and then add the last digit, so that it is divisable by 5? the number should always be 5 digits long. Second, how do I check it, I think I need to do something like...

        if (int x MOD 5 ==0)

        Or something like that. The first step is the most important though. Thank you, Steve

        L Offline
        L Offline
        Lost User
        wrote on last edited by
        #18

        Didn't you already post this in the Q&A and get an answer to it?? Generating numbers to the multiple of 5?[^]

        Computers have been intelligent for a long time now. It just so happens that the program writers are about as effective as a room full of monkeys trying to crank out a copy of Hamlet.

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        • D David1987

          Nope. You seem to think that that is the only definition of divisibility. I did not personally redefine anything. There is no natural number n such that 0/x=n so no x evenly divides 0. If you use the definition with integers instead of natural numbers, everything divides zero. Also, the prime factorization of zero is empty.

          L Offline
          L Offline
          Luc Pattyn
          wrote on last edited by
          #19

          natural numbers are the ordinary counting numbers 1, 2, 3, ... (sometimes zero is also included) is what Wikipedia[^] offers as a definition. Now you can choose: either you include zero and you are allowed to use it at both sides of your 0/x=n, or you exclude it (and then your "except zero" remark that started all this is completely irrelevant). :doh:

          Luc Pattyn [My Articles] Nil Volentibus Arduum

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          • OriginalGriffO OriginalGriff

            Luc Pattyn wrote:

            Next you'll state you could also redefine 5, so it no longer divides itself.

            It doesn't. There are only four bacon sandwiches left... :laugh:

            Real men don't use instructions. They are only the manufacturers opinion on how to put the thing together. Manfred R. Bihy: "Looks as if OP is learning resistant."

            L Offline
            L Offline
            Luc Pattyn
            wrote on last edited by
            #20

            Sorry for the late reply, I have been off-line this evening, I have another tournament going on this week. I trust all bacon sandwiches have magically disappeared by now, and so the problem got solved? :)

            Luc Pattyn [My Articles] Nil Volentibus Arduum

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            • S stephen darling

              riced wrote:

              If a number is divisible by 5 it must end in 5 or 0

              Yes; I was getting confused with the coding issue not the actual math.

              riced wrote:

              that's primary school arithmetic.

              I know, I am a Biomedical Scientist.

              riced wrote:

              If you don't believe me write out the 5 times table for the numbers 1 to 20.

              I do believe you. Like I said, it was the coding side of things. However, it is my fault the way I explained myself, it did indeed look as though I didn’t understand the math itself, and I certainly was not questioning you answer. Sorry if it came across that way, and thank you. Kind Regards, Stephen

              M Offline
              M Offline
              Mycroft Holmes
              wrote on last edited by
              #21

              Your confusion did lead me to think - how old is this guy, doesn't understand primary grade maths :-D

              Never underestimate the power of human stupidity RAH

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              • L Luc Pattyn

                natural numbers are the ordinary counting numbers 1, 2, 3, ... (sometimes zero is also included) is what Wikipedia[^] offers as a definition. Now you can choose: either you include zero and you are allowed to use it at both sides of your 0/x=n, or you exclude it (and then your "except zero" remark that started all this is completely irrelevant). :doh:

                Luc Pattyn [My Articles] Nil Volentibus Arduum

                D Offline
                D Offline
                David1987
                wrote on last edited by
                #22

                Yes but that's precisely the point, you can choose.

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                • D David1987

                  Generate a random integer in [2000, 19999] and multiply it by 5. The result will always be in [10000, 99999] (ie 5 decimal digits) and be divisible by 5 (by construction)

                  int yourNumber = 5 * rand.Next(2000, 20000); // remember the max-bound is exclusive
                  if (yourNumber % 5 != 0)
                  Console.WriteLine("the universe is wrong");

                  And make sure you reuse a single instance of Random, if you create new ones the result won't be random. [/spoon feeding]

                  S Offline
                  S Offline
                  stephen darling
                  wrote on last edited by
                  #23

                  David1987 wrote:

                  And make sure you reuse a single instance of Random,

                  How exactly do I ensure that I am doing this? I am using rand a number of times, and although I get different values, it does appear that they are very simular. Regards, Stephen

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                  • D David1987

                    Nope. You seem to think that that is the only definition of divisibility. I did not personally redefine anything. There is no natural number n such that 0/x=n so no x evenly divides 0. If you use the definition with integers instead of natural numbers, everything divides zero. Also, the prime factorization of zero is empty.

                    B Offline
                    B Offline
                    BobJanova
                    wrote on last edited by
                    #24

                    That is a stupid definition. It would also indicate that -10 is not divisible by 5. There may be abstruse mathematical concepts for which it's useful, I suppose, but for normal maths it is nonsense.

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                    • S stephen darling

                      Does this mean that no matter what number I generate, it will always have to end in 5? e.g. All these numbers are divisable by 5

                      39485
                      99045
                      12095
                      49385
                      99335

                      However, I was under the impression I could generate numbers that would be divisable by 5, but not end in 5? Is this wrong? Regards, Stephen

                      G Offline
                      G Offline
                      Gary Wheeler
                      wrote on last edited by
                      #25

                      All integers evenly divisible by 5 must end in either 5 or 0 when expressed in base 10. This is basic math.

                      Software Zen: delete this;

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                      • S stephen darling

                        Hi. First, how would I create a random number, and then add the last digit, so that it is divisable by 5? the number should always be 5 digits long. Second, how do I check it, I think I need to do something like...

                        if (int x MOD 5 ==0)

                        Or something like that. The first step is the most important though. Thank you, Steve

                        T Offline
                        T Offline
                        Tom Chantler
                        wrote on last edited by
                        #26

                        Is this a joke question? Generate a four digit number and add an extra number to the end, being either 5 or 0. Then don't check it because it will be correct!!! e.g. 4678; add 5 on the end to give 46785.

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                        • S stephen darling

                          Hi. First, how would I create a random number, and then add the last digit, so that it is divisable by 5? the number should always be 5 digits long. Second, how do I check it, I think I need to do something like...

                          if (int x MOD 5 ==0)

                          Or something like that. The first step is the most important though. Thank you, Steve

                          P Offline
                          P Offline
                          Paulo_JCG
                          wrote on last edited by
                          #27

                          Random random = new Random(); return (random.Next(17999) + 2000) * 5; this gives a number divisable by 5 between 10000 and 99995

                          Paulo Gomes Over and Out :D

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                          • S stephen darling

                            riced wrote:

                            If a number is divisible by 5 it must end in 5 or 0

                            Yes; I was getting confused with the coding issue not the actual math.

                            riced wrote:

                            that's primary school arithmetic.

                            I know, I am a Biomedical Scientist.

                            riced wrote:

                            If you don't believe me write out the 5 times table for the numbers 1 to 20.

                            I do believe you. Like I said, it was the coding side of things. However, it is my fault the way I explained myself, it did indeed look as though I didn’t understand the math itself, and I certainly was not questioning you answer. Sorry if it came across that way, and thank you. Kind Regards, Stephen

                            M Offline
                            M Offline
                            mmwlada
                            wrote on last edited by
                            #28

                            stephen.darling wrote:

                            riced wrote:

                            that's primary school arithmetic.

                            I know, I am a Biomedical Scientist.

                            You are NOT a scientist. A scinetist knows elementary math. You should be ashamed of yourself.

                            There can be only one.

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                            • M mmwlada

                              stephen.darling wrote:

                              riced wrote:

                              that's primary school arithmetic.

                              I know, I am a Biomedical Scientist.

                              You are NOT a scientist. A scinetist knows elementary math. You should be ashamed of yourself.

                              There can be only one.

                              S Offline
                              S Offline
                              stephen darling
                              wrote on last edited by
                              #29

                              mmwlada wrote:

                              You are NOT a scientist. A scinetist knows elementary math. You should be ashamed of yourself.

                              How dare you! I may be a beginner in the programming world, but to be spoken to in this way from someone who does not know me is extremely rude! I am indeed a scientist, registered in the UK as a practising biomedical scientist, not that I need to explain myself to you! As for the math, if you took the time to read through the post, you would see that I simply explained myself wrong, and it was the programming that I was struggling with, and not the math. As for being ashamed of myself; I do not know what your problem is, but believe me, I have nothing to be ashamed of, and could now go on to say allot about, and to you, however, I will refrain! Stephen

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                              • S stephen darling

                                riced wrote:

                                If a number is divisible by 5 it must end in 5 or 0

                                Yes; I was getting confused with the coding issue not the actual math.

                                riced wrote:

                                that's primary school arithmetic.

                                I know, I am a Biomedical Scientist.

                                riced wrote:

                                If you don't believe me write out the 5 times table for the numbers 1 to 20.

                                I do believe you. Like I said, it was the coding side of things. However, it is my fault the way I explained myself, it did indeed look as though I didn’t understand the math itself, and I certainly was not questioning you answer. Sorry if it came across that way, and thank you. Kind Regards, Stephen

                                F Offline
                                F Offline
                                FunkySteve
                                wrote on last edited by
                                #30

                                Actually, every number is divisible by 5.

                                S 1 Reply Last reply
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                                • F FunkySteve

                                  Actually, every number is divisible by 5.

                                  S Offline
                                  S Offline
                                  stephen darling
                                  wrote on last edited by
                                  #31

                                  FunkySteve wrote:

                                  Actually, every number is divisible by 5

                                  True. Again, my fault for not explaining properly. I meant a modulus of zero, so that 13285 MOD 5 = 0 Got it all sorted now, thanx to most people, disregarding one perticular ignorant comment :confused: Thank you, Steve

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                                  • L Luc Pattyn

                                    a random multiple of five is bound to be five times some other random number. :omg:

                                    Luc Pattyn [My Articles] Nil Volentibus Arduum

                                    F Offline
                                    F Offline
                                    Fabio Franco
                                    wrote on last edited by
                                    #32

                                    I'd say you're stating the obvious, but then, I remember when I was very young and inexperienced and I couldn't see stuff like this. So, it's not always obvious as one might think. You got my five.

                                    "To alcohol! The cause of, and solution to, all of life's problems" - Homer Simpson

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                                    • S stephen darling

                                      Does this mean that no matter what number I generate, it will always have to end in 5? e.g. All these numbers are divisable by 5

                                      39485
                                      99045
                                      12095
                                      49385
                                      99335

                                      However, I was under the impression I could generate numbers that would be divisable by 5, but not end in 5? Is this wrong? Regards, Stephen

                                      K Offline
                                      K Offline
                                      Kenneth Kasajian
                                      wrote on last edited by
                                      #33

                                      Is this discussion really taking place? What is this, 3rd grade?

                                      ken@kasajian.com / www.kasajian.com

                                      S 1 Reply Last reply
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                                      • F Fabio Franco

                                        I'd say you're stating the obvious, but then, I remember when I was very young and inexperienced and I couldn't see stuff like this. So, it's not always obvious as one might think. You got my five.

                                        "To alcohol! The cause of, and solution to, all of life's problems" - Homer Simpson

                                        L Offline
                                        L Offline
                                        Luc Pattyn
                                        wrote on last edited by
                                        #34

                                        I tend to state facts, even obvious ones, especially when it seems to OP is missing them somehow. Rather than spoon feeding, I prefer to give a gentle push in the right direction... :)

                                        Luc Pattyn [My Articles] Nil Volentibus Arduum

                                        F 1 Reply Last reply
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                                        • K Kenneth Kasajian

                                          Is this discussion really taking place? What is this, 3rd grade?

                                          ken@kasajian.com / www.kasajian.com

                                          S Offline
                                          S Offline
                                          stephen darling
                                          wrote on last edited by
                                          #35

                                          Kenneth Kasajian wrote:

                                          Is this discussion really taking place? What is this, 3rd grade?

                                          What is everones problem? I asked how to solve a basic math based problem PROGMATICALLY as I am a beginner when it comes to c#, and I am wishing I never bothered asking! Although, there are a number of people who have offered working solutions. Why must people post such a responce as yours? Did your post really help in anyway? Regards, Stephen

                                          K 1 Reply Last reply
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