Pigeonhole Principle - Pairs of Sets with distinct sums
104309
Pigeon-Hole Principle Common Sum
151935
Proving the predicate $\forall n \in \mathbb{N} , n \geq 2$ using the Pigeonhole principle
148399
Two sets which contain each other as elements
75852
Using Pigeonhole Principle to prove two numbers in a subset of $[2n]$ divide each other
158882
Prove the existence of some weird family of sets
78163
Hint for problem on $4 \times 7$-chessboard problem related to pigeonhole principle
150324
Pigeonhole principle: prove that any set of $n+1$ integers from $\{1,2,...,2n\}$ has two consecutive integers differ by one.
135743
Collection of subset generating every pairs of elements
142978
combinatorics: sum of product of integer compositions
61747
Proof of exchange principle in set theory
144821
Number of ordered pairs of subsets
68882
Path to Combinatorics Problem [$1.11$]
72256
Prove there exists two sub-sets of indices $I,J\subseteq [2n]$ such that $\sum_{i\in I}a_i=\sum_{j\in J}b_j$
14687
Is it possible to easily count all the possible distinct sums from distinct numbers?
105886
A question on the proof of 14 distinct sets can be formed by complementation and closure
53312
Multiplication principle and permutation
70143
Mutually exclusive countable subsets of a countable set