In a school consisting of 2019 pupils, any pair of pupils have exactly one common friend. Determine the smallest possible value of the difference between the numbers of friends of the pupil with the most friends and the pupil with the least friends in this school.
Correct Solutions by,
- Toshihiro Shimizu Kawasaki, Japan
- M. Lütfü Yarar Istanbul Technical University
- Susanne Tegler Lund, Sweden
- Yusuf Kanat Ömer Halisdemir University, Niğde
- Serdar Hojayev Dashoguz, Turkmenistan
- Frank Feys Lahey, The Netherlands