Proving three people must be mutually friends, enemies, or strangers
74961
Prove that every edge-coloring of $K_{17}$ with $3$ colors contains a monochromatic $K_3$.
45204
Combinatorial proofs: having a difficult time understanding how to write them out
61671
Discrete Math: Writing Proofs
60640
2-party private set intersection
79686
How can I prove these statements?
73334
Proving this relation is transitive
121605
A coin tossing game which leads to a contradiction
44943
The 3 different equals
125174
Combinatorial intuition of identity
94295
Pigeonhole-principle with two choices
151561
Proving 'Law of Excluded Middle' in Fitch system
141800
Peer to Peer: Methods of Finding Peers
109273
Extending the birthday paradox to more than 2 people
134440
An unexpected application of non-trivial combinatorics
21598
A game of guessing a chosen number
125263
How to crack the proof
141529
Proving existence of a minimum