RMO 2009
Indian Regional Mathematical Olympiad 2009.
The official paper in 1 language
Other problems
Show that can be written as product of two positive integers each of which is larger than .
A convex polygon is such that the distance between any two vertices does not exceed . Prove that the distance between any two points on the boundary of the polygon does not exceed . If and are two distinct points inside the polygon, prove that there exists a point on the boundary of the polygon such that .
In a book with page numbers from to some pages are torn off. The sum of the numbers on the remaining pages is . How many pages are torn off?