Cardinality of $A = varnothing, B = varnothing , C = varnothing$

The name of the pictureThe name of the pictureThe name of the pictureClash Royale CLAN TAG#URR8PPP











up vote
1
down vote

favorite












Given three sets $A = varnothing, B = varnothing , C = varnothing$ what are the cardinalities of those sets ?
Obviously cardinality of $A$ is $0$ and cardinality of $B$ is $1$, but I am not sure about set $C$, because some sources say that cardinality of such set is $2$. Can you please clarify this to me ?







share|cite|improve this question





















  • Have you computed its power set?
    – Javi
    Jul 29 at 19:43






  • 2




    By power do you mean cardinality?
    – user223391
    Jul 29 at 19:45










  • @ZacharySelk yes, edited
    – Kevin
    Jul 29 at 19:47














up vote
1
down vote

favorite












Given three sets $A = varnothing, B = varnothing , C = varnothing$ what are the cardinalities of those sets ?
Obviously cardinality of $A$ is $0$ and cardinality of $B$ is $1$, but I am not sure about set $C$, because some sources say that cardinality of such set is $2$. Can you please clarify this to me ?







share|cite|improve this question





















  • Have you computed its power set?
    – Javi
    Jul 29 at 19:43






  • 2




    By power do you mean cardinality?
    – user223391
    Jul 29 at 19:45










  • @ZacharySelk yes, edited
    – Kevin
    Jul 29 at 19:47












up vote
1
down vote

favorite









up vote
1
down vote

favorite











Given three sets $A = varnothing, B = varnothing , C = varnothing$ what are the cardinalities of those sets ?
Obviously cardinality of $A$ is $0$ and cardinality of $B$ is $1$, but I am not sure about set $C$, because some sources say that cardinality of such set is $2$. Can you please clarify this to me ?







share|cite|improve this question













Given three sets $A = varnothing, B = varnothing , C = varnothing$ what are the cardinalities of those sets ?
Obviously cardinality of $A$ is $0$ and cardinality of $B$ is $1$, but I am not sure about set $C$, because some sources say that cardinality of such set is $2$. Can you please clarify this to me ?









share|cite|improve this question












share|cite|improve this question




share|cite|improve this question








edited Jul 29 at 19:53









Cornman

2,30021027




2,30021027









asked Jul 29 at 19:41









Kevin

184




184











  • Have you computed its power set?
    – Javi
    Jul 29 at 19:43






  • 2




    By power do you mean cardinality?
    – user223391
    Jul 29 at 19:45










  • @ZacharySelk yes, edited
    – Kevin
    Jul 29 at 19:47
















  • Have you computed its power set?
    – Javi
    Jul 29 at 19:43






  • 2




    By power do you mean cardinality?
    – user223391
    Jul 29 at 19:45










  • @ZacharySelk yes, edited
    – Kevin
    Jul 29 at 19:47















Have you computed its power set?
– Javi
Jul 29 at 19:43




Have you computed its power set?
– Javi
Jul 29 at 19:43




2




2




By power do you mean cardinality?
– user223391
Jul 29 at 19:45




By power do you mean cardinality?
– user223391
Jul 29 at 19:45












@ZacharySelk yes, edited
– Kevin
Jul 29 at 19:47




@ZacharySelk yes, edited
– Kevin
Jul 29 at 19:47










3 Answers
3






active

oldest

votes

















up vote
2
down vote



accepted










$$A = varnothing, B = varnothing , C = varnothing$$



The way you have it $B$ and $C$ both have cardinality of $1$



My guess is that you wanted $$C = varnothing ,varnothing$$



Which has cardinality $2$.






share|cite|improve this answer




























    up vote
    1
    down vote













    The cardinality of $A$ is 0. The cardinality of $B$ and $C$ is both 1. For $B$ it is clear. $C$ just contains one element as well. This is the set that contains the emptyset $emptyset$. Namely $B$. One could write $C=B$, which makes it clear.






    share|cite|improve this answer




























      up vote
      1
      down vote













      The power set of $emptyset$ is indeed $lbrace emptyset rbrace$, as the only subset of $emptyset$ is $emptyset$ itself.



      The power set of $lbrace emptyset rbrace$ indeed does have two elements: $emptyset$ and the set itself: $lbrace emptyset rbrace$, thus making it $lbrace lbrace emptyset rbrace, emptyset rbrace$.






      share|cite|improve this answer





















      • There was a typo in the question. It is asked for the cardinality and not the power set.
        – Cornman
        Jul 29 at 19:54






      • 1




        @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
        – Theo Bendit
        Jul 29 at 19:56










      • Possible, thats why I upvoted your answer.
        – Cornman
        Jul 29 at 19:57










      Your Answer




      StackExchange.ifUsing("editor", function ()
      return StackExchange.using("mathjaxEditing", function ()
      StackExchange.MarkdownEditor.creationCallbacks.add(function (editor, postfix)
      StackExchange.mathjaxEditing.prepareWmdForMathJax(editor, postfix, [["$", "$"], ["\\(","\\)"]]);
      );
      );
      , "mathjax-editing");

      StackExchange.ready(function()
      var channelOptions =
      tags: "".split(" "),
      id: "69"
      ;
      initTagRenderer("".split(" "), "".split(" "), channelOptions);

      StackExchange.using("externalEditor", function()
      // Have to fire editor after snippets, if snippets enabled
      if (StackExchange.settings.snippets.snippetsEnabled)
      StackExchange.using("snippets", function()
      createEditor();
      );

      else
      createEditor();

      );

      function createEditor()
      StackExchange.prepareEditor(
      heartbeatType: 'answer',
      convertImagesToLinks: true,
      noModals: false,
      showLowRepImageUploadWarning: true,
      reputationToPostImages: 10,
      bindNavPrevention: true,
      postfix: "",
      noCode: true, onDemand: true,
      discardSelector: ".discard-answer"
      ,immediatelyShowMarkdownHelp:true
      );



      );








       

      draft saved


      draft discarded


















      StackExchange.ready(
      function ()
      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2866357%2fcardinality-of-a-varnothing-b-varnothing-c-varnothing%23new-answer', 'question_page');

      );

      Post as a guest






























      3 Answers
      3






      active

      oldest

      votes








      3 Answers
      3






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes








      up vote
      2
      down vote



      accepted










      $$A = varnothing, B = varnothing , C = varnothing$$



      The way you have it $B$ and $C$ both have cardinality of $1$



      My guess is that you wanted $$C = varnothing ,varnothing$$



      Which has cardinality $2$.






      share|cite|improve this answer

























        up vote
        2
        down vote



        accepted










        $$A = varnothing, B = varnothing , C = varnothing$$



        The way you have it $B$ and $C$ both have cardinality of $1$



        My guess is that you wanted $$C = varnothing ,varnothing$$



        Which has cardinality $2$.






        share|cite|improve this answer























          up vote
          2
          down vote



          accepted







          up vote
          2
          down vote



          accepted






          $$A = varnothing, B = varnothing , C = varnothing$$



          The way you have it $B$ and $C$ both have cardinality of $1$



          My guess is that you wanted $$C = varnothing ,varnothing$$



          Which has cardinality $2$.






          share|cite|improve this answer













          $$A = varnothing, B = varnothing , C = varnothing$$



          The way you have it $B$ and $C$ both have cardinality of $1$



          My guess is that you wanted $$C = varnothing ,varnothing$$



          Which has cardinality $2$.







          share|cite|improve this answer













          share|cite|improve this answer



          share|cite|improve this answer











          answered Jul 29 at 19:54









          Mohammad Riazi-Kermani

          27.3k41851




          27.3k41851




















              up vote
              1
              down vote













              The cardinality of $A$ is 0. The cardinality of $B$ and $C$ is both 1. For $B$ it is clear. $C$ just contains one element as well. This is the set that contains the emptyset $emptyset$. Namely $B$. One could write $C=B$, which makes it clear.






              share|cite|improve this answer

























                up vote
                1
                down vote













                The cardinality of $A$ is 0. The cardinality of $B$ and $C$ is both 1. For $B$ it is clear. $C$ just contains one element as well. This is the set that contains the emptyset $emptyset$. Namely $B$. One could write $C=B$, which makes it clear.






                share|cite|improve this answer























                  up vote
                  1
                  down vote










                  up vote
                  1
                  down vote









                  The cardinality of $A$ is 0. The cardinality of $B$ and $C$ is both 1. For $B$ it is clear. $C$ just contains one element as well. This is the set that contains the emptyset $emptyset$. Namely $B$. One could write $C=B$, which makes it clear.






                  share|cite|improve this answer













                  The cardinality of $A$ is 0. The cardinality of $B$ and $C$ is both 1. For $B$ it is clear. $C$ just contains one element as well. This is the set that contains the emptyset $emptyset$. Namely $B$. One could write $C=B$, which makes it clear.







                  share|cite|improve this answer













                  share|cite|improve this answer



                  share|cite|improve this answer











                  answered Jul 29 at 19:50









                  Cornman

                  2,30021027




                  2,30021027




















                      up vote
                      1
                      down vote













                      The power set of $emptyset$ is indeed $lbrace emptyset rbrace$, as the only subset of $emptyset$ is $emptyset$ itself.



                      The power set of $lbrace emptyset rbrace$ indeed does have two elements: $emptyset$ and the set itself: $lbrace emptyset rbrace$, thus making it $lbrace lbrace emptyset rbrace, emptyset rbrace$.






                      share|cite|improve this answer





















                      • There was a typo in the question. It is asked for the cardinality and not the power set.
                        – Cornman
                        Jul 29 at 19:54






                      • 1




                        @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                        – Theo Bendit
                        Jul 29 at 19:56










                      • Possible, thats why I upvoted your answer.
                        – Cornman
                        Jul 29 at 19:57














                      up vote
                      1
                      down vote













                      The power set of $emptyset$ is indeed $lbrace emptyset rbrace$, as the only subset of $emptyset$ is $emptyset$ itself.



                      The power set of $lbrace emptyset rbrace$ indeed does have two elements: $emptyset$ and the set itself: $lbrace emptyset rbrace$, thus making it $lbrace lbrace emptyset rbrace, emptyset rbrace$.






                      share|cite|improve this answer





















                      • There was a typo in the question. It is asked for the cardinality and not the power set.
                        – Cornman
                        Jul 29 at 19:54






                      • 1




                        @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                        – Theo Bendit
                        Jul 29 at 19:56










                      • Possible, thats why I upvoted your answer.
                        – Cornman
                        Jul 29 at 19:57












                      up vote
                      1
                      down vote










                      up vote
                      1
                      down vote









                      The power set of $emptyset$ is indeed $lbrace emptyset rbrace$, as the only subset of $emptyset$ is $emptyset$ itself.



                      The power set of $lbrace emptyset rbrace$ indeed does have two elements: $emptyset$ and the set itself: $lbrace emptyset rbrace$, thus making it $lbrace lbrace emptyset rbrace, emptyset rbrace$.






                      share|cite|improve this answer













                      The power set of $emptyset$ is indeed $lbrace emptyset rbrace$, as the only subset of $emptyset$ is $emptyset$ itself.



                      The power set of $lbrace emptyset rbrace$ indeed does have two elements: $emptyset$ and the set itself: $lbrace emptyset rbrace$, thus making it $lbrace lbrace emptyset rbrace, emptyset rbrace$.







                      share|cite|improve this answer













                      share|cite|improve this answer



                      share|cite|improve this answer











                      answered Jul 29 at 19:53









                      Theo Bendit

                      11.8k1841




                      11.8k1841











                      • There was a typo in the question. It is asked for the cardinality and not the power set.
                        – Cornman
                        Jul 29 at 19:54






                      • 1




                        @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                        – Theo Bendit
                        Jul 29 at 19:56










                      • Possible, thats why I upvoted your answer.
                        – Cornman
                        Jul 29 at 19:57
















                      • There was a typo in the question. It is asked for the cardinality and not the power set.
                        – Cornman
                        Jul 29 at 19:54






                      • 1




                        @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                        – Theo Bendit
                        Jul 29 at 19:56










                      • Possible, thats why I upvoted your answer.
                        – Cornman
                        Jul 29 at 19:57















                      There was a typo in the question. It is asked for the cardinality and not the power set.
                      – Cornman
                      Jul 29 at 19:54




                      There was a typo in the question. It is asked for the cardinality and not the power set.
                      – Cornman
                      Jul 29 at 19:54




                      1




                      1




                      @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                      – Theo Bendit
                      Jul 29 at 19:56




                      @Cornman I'm not convinced. I think the OP is confused between cardinality and power set. I think the heart of the confusion is that he thinks $lbrace emptyset rbrace$ might be a one-element set that breaks the rule $|mathcalP(S)| = 2^S$.
                      – Theo Bendit
                      Jul 29 at 19:56












                      Possible, thats why I upvoted your answer.
                      – Cornman
                      Jul 29 at 19:57




                      Possible, thats why I upvoted your answer.
                      – Cornman
                      Jul 29 at 19:57












                       

                      draft saved


                      draft discarded


























                       


                      draft saved


                      draft discarded














                      StackExchange.ready(
                      function ()
                      StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fmath.stackexchange.com%2fquestions%2f2866357%2fcardinality-of-a-varnothing-b-varnothing-c-varnothing%23new-answer', 'question_page');

                      );

                      Post as a guest













































































                      Comments

                      Popular posts from this blog

                      What is the equation of a 3D cone with generalised tilt?

                      Color the edges and diagonals of a regular polygon

                      Relationship between determinant of matrix and determinant of adjoint?