An interior point of a finite planar point set is a point of the set that is not on the boundary of the convex hull of the set. For any integer k ≥ 1, let h（κ） be the smallest integer such that every set of points in the plane, no three collinear, with at least h（κ） interior points, has a subset of points with exactly κ or κ ＋ 1 interior points of P. We prove that h（5）=11.
By the fxed point index theory, the existence of one, two and three positive solutions to(k, n-k) conjugate boundary value problems is obtained, where n > 2, 1 ≤ k ≤ n-1, the nonlinear term may be noncontinuous and singular at any point of [0,1]. Our results extend some of the existent results.
