2

Part of 1982 Poland - Second Round

Problems(1)

each point of plane belongs to at most 5 circles.

Source: Polish MO Recond Round 1982 p2

The plane is covered with circles in such a way that the center of each circle does not belong to any other circle. Prove that each point of the plane belongs to at most five circles.

geometrycombinatoricscombinatorial geometry