Cardinality of $A = varnothing, B = varnothing , C = varnothing$
Clash 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 ?
discrete-mathematics elementary-set-theory
add a comment |Â
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 ?
discrete-mathematics elementary-set-theory
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
add a comment |Â
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 ?
discrete-mathematics elementary-set-theory
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 ?
discrete-mathematics elementary-set-theory
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
add a comment |Â
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
add a comment |Â
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 $2$.
add a comment |Â
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.
add a comment |Â
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 $lbrace lbrace emptyset rbrace, emptyset rbrace$.
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
add a comment |Â
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 $2$.
add a comment |Â
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 $2$.
add a comment |Â
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 $2$.
$$A = varnothing, B = varnothing , C = varnothing$$
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 $2$.
answered Jul 29 at 19:54


Mohammad Riazi-Kermani
27.3k41851
27.3k41851
add a comment |Â
add a comment |Â
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.
add a comment |Â
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.
add a comment |Â
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.
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.
answered Jul 29 at 19:50
Cornman
2,30021027
2,30021027
add a comment |Â
add a comment |Â
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 $lbrace lbrace emptyset rbrace, emptyset rbrace$.
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
add a comment |Â
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 $lbrace lbrace emptyset rbrace, emptyset rbrace$.
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
add a comment |Â
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 $lbrace lbrace emptyset rbrace, emptyset rbrace$.
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 $lbrace lbrace emptyset rbrace, emptyset rbrace$.
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
add a comment |Â
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
add a comment |Â
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
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
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Sign up or log in
StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
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