English Információ A lap Pontverseny Cikkek Hírek Fórum

Rendelje meg a KöMaL-t!

VersenyVizsga portál

Kísérletek.hu

Matematika oktatási portál

A. 641. Determine whether there is a finite, nonempty subset $\displaystyle S$ of the square grid in the plane such that every element of $\displaystyle S$ has at least two neighbours in $\displaystyle S$ and $\displaystyle S$ does not contain four points that are the vertices of a square (with sides not necessary parallel to the coordinate axes)?

Proposed by: Mátyás Sustik, San Francisco

(5 points)

Deadline expired on 11 May 2015.

Statistics on problem A. 641.
 1 student sent a solution. 5 points: Fehér Zsombor.

• Problems in Mathematics of KöMaL, April 2015

•  Támogatóink: Morgan Stanley