MathDB

187

Part of 1950 Moscow Mathematical Olympiad

Problems(1)

MMO 187 Moscow MO 1950 draw 10 bus routes with stops

Source:

8/6/2019
Is it possible to draw 1010 bus routes with stops such that for any 88 routes there is a stop that does not belong to any of the routes, but any 99 routes pass through all the stops?
combinatorics