Problem A. 370. (March 2005)
A. 370. For any two guests on a party of kn participants there is some guest who knows both of them. Prove that if then one can find n guests who together know everyone else.
Deadline expired on April 15, 2005.
3 students sent a solution. 5 points: Jankó Zsuzsanna, Paulin Roland. 4 points: Strenner Balázs.