Why is $2^n$ the maximum number of subsets of a set of size $n$?
51617
What is the proof that the total number of subsets of a set is $2^n$?
11817
Proving that every set $A \subset \Bbb N$ of size $n$ contains a subset $B \subset A$ with $n | \sum_{b \in B} b$
57644
Lower bounds for ${{2n} \choose {n}}$
73345
maximum size of a $k$-intersecting family of $[n]$
147484
For a set with N members, what is the number of set partitions in which each subset is either of size 1 or 2?
138643
Prove that at most $2k+1$ independent sets form the set of vertices of a graph, where $k$ is the maximum degree.
60309
Let X be a subset of {1,2,...,2014}...
111954
Computing the cardinality of a combinatorial set
110559
Why is the minimum size of a generating set for a finite group at most $\log_2 n$?
65978
How many subsets does the set $\{1, 2, \dots , n\}$ have that contain no two consecutive integers if $1$ and $n$ also count as consecutive?
59535
Prove that there exists such a set of $n$ positive integers
25834
Proof a set cannot contain its own powerset - Russell's Paradox
33894
How many chains are there in a finite power set?
27889
If the set of odd numbers is a subset of $\mathbb N$ then surely it is smaller than $\mathbb N$
4776
Prove that the power set of an $n$-element set contains $2^n$ elements
11967
number of subsets of even and odd
139155
What does 2 to the power x mean in set theory