MathDB
problems in competition

Source: Italy TST 2000

September 27, 2008
combinatorics unsolvedcombinatorics

Problem Statement

On a mathematical competition n n problems were given. The final results showed that: (i) on each problem, exactly three contestants scored 7 7 points; (ii) for each pair of problems, exactly one contestant scored 7 7 points on both problems. Prove that if n8 n \geq 8, then there is a contestant who got 7 7 points on each problem. Is this statement necessarily true if n \equal{} 7?