MathDB
ISI 2024 P8

Source: college entrance

May 12, 2024
combinatoricsTournamentgraph theoryISI 2024

Problem Statement

In a sports tournament involving NN teams, each team plays every other team exactly one. At the end of every match, the winning team gets 11 point and losing team gets 00 points. At the end of the tournament, the total points received by the individual teams are arranged in decreasing order as follows: x1x2xN.x_1 \ge x_2 \ge \cdots \ge x_N . Prove that for any 1kN1\le k \le N, Nk2xkNk+12\frac{N - k}{2} \le x_k \le N - \frac{k+1}{2}