olymmath

KURSCHAK 2017

Kürschák Competition 2017.

Other problems

Problem 1

Let ABCABC be a triangle. Choose points A′A' , B′B' and C′C' independently on side segments BCBC , CACA and ABAB respectively with a uniform distribution. For a point ZZ in the plane, let p(Z)p(Z) denote the probability that ZZ is contained in the triangle enclosed by lines AA′AA' , BB′BB' and CC′CC' . For which interior point ZZ in triangle ABCABC is p(Z)p(Z) maximised?

Problem 2

Do there exist polynomials p(x)p(x) and q(x)q(x) with real coefficients such that p3(x)−q2(x)p^3(x)-q^2(x) is linear but not constant?

Problem 3

An nn by nn table has an integer in each cell, such that no two cells within a row share the same number. Prove that it is possible to permute the elements within each row to obtain a table that has nn distinct numbers in each column.