Cardinality of ordered pairs of subsets of {1, ..., n} computed in 2 different ways
90519
Combinatorial proof of $\sum\limits_{k=0}^n {n \choose k}3^k=4^n$
81509
The cardinality of a countable union of countable sets, without the axiom of choice
113668
Uncountable chain of subsets of $\mathbb N$
118560
Ordered N-Tuples as Cartesian Products of Indexed Families
153072
Guessing a subset of $\{1,...,N\}$
93330
Cardinality of all cardinalities
79568
Cardinality of the set $D$
39880
Cardinality of Orderings of $\mathbb{R}$
23442
Cardinality of the union of infinite and countable sets
83518
Proving Two sets have same cardinality
142886
Find set with maximal cardinality given constraints
108957
Cardinality of a totally ordered union
70164
Proof exercise that the cardinal number of a set in $\mathbb R^2$ is $\frak c$
73350
Geometric solution to find a Set of totally ordered Subsets of $ \mathbb{N} $ is uncountable
41783
Cardinality of the Cartesian Product of Two Equinumerous Infinite Sets
62687
Proving Cardinality of Cosets in Abstract Algebra
65768
What is the cardinality of the set of the empty set?