Integers on real axis
Source: Turkish NMO 1996, 3. Problem
July 31, 2011
combinatorics proposedcombinatorics
Problem Statement
Let integers on the real axis be colored. Determine for which positive integers there exists a family of closed intervals with the following properties:
i) The union of the intervals in contains all of the colored points;
ii) Any two distinct intervals in are disjoint;
iii) For each interval at we have , where denotes the number of integers in , and the number of colored integers in .