Let S = {1, 2, . . . , 2019} and A1, A2, . . . , An be subsets of S such that the union of any
three of them is equal to S and the union of any two of them is not equal to S.
Find the maximal possible value of n.
Correct Solutions by,
- Toshihiro Shimizu Kawasaki, Japan
- Murat Chashmetov TSU Turkmenistan
- Bora Ege Duygun Bilkent University
- Magnus Jakobsson Lund, Sweden
- Roger Bengtsson Lund, Sweden
- Max Nilsson Lund, Sweden
- Steffen Weber Ismanıng, Germany
- İrem Nur Çevikcan Buca İnci Özer Tırnaklı Fen Lisesi
- Feray Lina Yence Buca İnci Özer Tırnaklı Fen Lisesi
- Asude Ebrar Kızıloğlu Kadıköy Özel Eğitmen Fen ve Anadolu Lisesi
- Ayşe Zehra Şen İstanbul Lisesi
- Hasan Zübeyr Demir Özel Ankara Çağlayan Fen Lisesi
- Sude Filiz İzmir Bilfen Fen Lisesi
- Serdar Hojayev Dashoguz, Turkmenistan
Solution: http://www.fen.bilkent.edu.tr/~cvmath/Problem/1905a.pdf