Let x1,x2,…,xn be some numbers belonging to the interval [0,1]. Prove that on this segment there is a number x such that 1n(|x−x1|+|x−x2|+⋯+|x−xn|)=1/2.
A convex figure and point A inside it are given. Prove that there is a chord (that is, a segment joining two boundary points of a convex figure) passing through point A and dividing it in half at point A.