MathDB

The world and the european champion are determined in the same tournament carried in one round. There are

20

teams and

k

of them are european. The european champion is determined according to the results of the games only between those

k

teams. What is the greatest

k

such that the situation, when the single european champion is the single world outsider, is possible if:
a) it is hockey (draws allowed)?
b) it is volleyball (no draws)?

Problem Statement