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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

    D Offline
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    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

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      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.

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        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."

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          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

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            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

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              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]

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                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.

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                  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

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                    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

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                      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

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                        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

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                          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.

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                            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

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                              FunkySteve
                              wrote on last edited by
                              #30

                              Actually, every number is divisible by 5.

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                              • F FunkySteve

                                Actually, every number is divisible by 5.

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                                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

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                                  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

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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

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                                      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

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                                      • K Kenneth Kasajian

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

                                        ken@kasajian.com / www.kasajian.com

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                                        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

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                                        • L Luc Pattyn

                                          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

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                                          F Offline
                                          Fabio Franco
                                          wrote on last edited by
                                          #36

                                          Completely agree, I'm totally against the "gimme codezzzz plz" culture.

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

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