1.if A is a set, give two subsets of A.
2. (a) if A and B are finite sets and A is a proper subset of B, what can u say about the cardinalities of the two sets??
(b) if the cardinality of A is less than the cardinality of B, does it follow that A is a proper subset of B??
3.if A and B have the same cardinality, does it follow that A=B? Explain.



Sagot :

1. If A is a set, two subsets are set A itself and an empty set { }.
2. (a) The cardinality of A is less than set B. If it is greater than or equal to B's cardinality then it is not a proper subset.
(b) Not necessarily since we are not sure if they have the same terms, but it is possible.
3. No since A=B means they are equal - that is exactly the same and wes only have the same cardinality which means they are only equivalent.