New posts in extremal-combinatorics

Number of unique pairings of k values.

combinatorics extremal-combinatorics

maximum size of a $k$-intersecting family of $[n]$

combinatorics extremal-combinatorics

Sperner's theorem on antichains - where does it come from?

math-history extremal-combinatorics

Maximum area of triangle inside a convex polygon

combinatorics polyhedra combinatorial-geometry extremal-combinatorics convex-geometry

An invisible ghost jumping on a regular hexagon

combinatorics puzzle combinatorial-game-theory extremal-combinatorics

Maximum distance between points in a triangle

geometry optimization contest-math combinatorial-geometry extremal-combinatorics

For a graph $G$, why should one expect the ratio $\text{ex} (n;G)/ \binom n2$ to converge?

graph-theory extremal-combinatorics

Riordan numbers recurrence

combinatorics discrete-mathematics recurrence-relations extremal-combinatorics catalan-numbers

How many non-isomorphic ways a convex polygon with $n + 2$ sides can be cut into triangles?

combinatorics graph-theory extremal-combinatorics

Maximum odd number of subsets, each intersects exactly half of the others

combinatorics combinatorial-geometry extremal-combinatorics

Minimum Cake Cutting for a Party

combinatorics number-theory graph-theory extremal-combinatorics hypergraphs

If any triangle has area at most 1 , points can be covered by a rectangle of area 2.

euclidean-geometry extremal-combinatorics combinatorial-geometry

Minimum number of balanced partitions

combinatorics binomial-coefficients extremal-combinatorics

Domination problem with sets

combinatorics algorithms discrete-optimization extremal-combinatorics probabilistic-method

Hypercube and Hyperspheres

algebraic-geometry euclidean-geometry integer-lattices combinatorial-geometry extremal-combinatorics

Minimum number of integer-sided squares needed to tile an $m$ by $n$ rectangle.

combinatorics number-theory packing-problem tiling extremal-combinatorics

A Knight and Knave Problem

discrete-mathematics logic puzzle combinatorial-game-theory extremal-combinatorics

Number of steps the path-avoiding snail must take before a step size of $(2n - 1)/2^k$?

combinatorics random-walk extremal-combinatorics

We have $n$ charged and $n$ uncharged batteries and a radio which needs two charged batteries to work.

combinatorics graph-theory contest-math discrete-optimization extremal-combinatorics

A conference uses $4$ main languages. Prove that there is a language that at least $\dfrac{3}{5}$ of the delegates know.

combinatorics discrete-mathematics contest-math extremal-combinatorics algebraic-combinatorics