MathDB

C2

Part of 2016 Balkan MO Shortlist

Problems(1)

2016 costumers in a shop on a particular day, maximal wanted

Source: Balkan BMO Shortlist 2016 C2

7/30/2019
There are 20162016 costumers who entered a shop on a particular day. Every customer entered the shop exactly once. (i.e. the customer entered the shop, stayed there for some time and then left the shop without returning back.) Find the maximal kk such that the following holds: There are kk customers such that either all of them were in the shop at a speci c time instance or no two of them were both in the shop at any time instance.
combinatoricsMaximal