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Source: 2024 CTST P24
March 29, 2024
combinatorics2024 CTSTexpected value
Problem Statement
Let . is a square in the Cartesian plane with side length and the sides parallel to the coordinate axes. Inside there are points , , , all of which have different coordinates, and the absolute value of the slope of any connected line between these points is at most . Prove that there exists a line such that at least of these points is at most distance away from .