olymmath

RS-SMO 2009

Serbian Mathematical Olympiad 2009.

Official paper

The official paper in 1 language

Serbian

Other problems

Problem 1

In a scalene triangle ABCABC , α\alpha and β\beta respectively denote the interior angles at vertixes AA and BB . The bisectors of these two angles meet the opposite sides of the triangle at points DD and EE , respectively. Prove that the acute angle between the lines DEDE and ABAB does not exceed ∣α−β∣3\frac{ | \alpha - \beta |}{3} . Proposed by Dusan Djukic

Problem 2

Find the smallest natural number which is a multiple of 20092009 and whose sum of (decimal) digits equals 20092009 Proposed by Milos Milosavljevic