IMO Shortlist 2007 problem C7


Kvaliteta:
  Avg: 0,0
Težina:
  Avg: 9,0
Dodao/la: arhiva
2. travnja 2012.
LaTeX PDF
Let \alpha < \frac {3 - \sqrt {5}}{2} be a positive real number. Prove that there exist positive integers n and p > \alpha \cdot 2^n for which one can select 2 \cdot p pairwise distinct subsets S_1, \ldots, S_p, T_1, \ldots, T_p of the set \{1,2, \ldots, n\} such that S_i \cap T_j \neq \emptyset for all 1 \leq i,j \leq p

Author: Gerhard Wöginger, Austria
Izvor: Međunarodna matematička olimpijada, shortlist 2007