Let P be a set of n≥2 distinct points in the plane, which does not contain any triplet of aligned points. Let S be the set of all segments whose endpoints are points of P. Given two segments s1,s2∈S, we write s1⊗s2 if the intersection of s1 with s2 is a point other than the endpoints of s1 and s2. Prove that there exists a segment s0∈S such that the set {s∈S∣s0⊗s} has at least 151(2n−2) elements combinatoricscombinatorics unsolved