MathDB
Problems
Contests
Undergraduate contests
Putnam
1979 Putnam
A4
A4
Part of
1979 Putnam
Problems
(1)
Putnam 1979 A4
Source:
4/8/2022
Let
A
A
A
be a set of
2
n
2n
2
n
points in the plane, no three of which are collinear. Suppose that
n
n
n
of them are colored red and the remaining
n
n
n
blue. Prove or disprove: there are
n
n
n
closed straight line segments, no two with a point in common, such that the endpoints of each segment are points of
A
A
A
having different colors.
college contests