Skip to content / Đến nội dung
ThichHocToan.com

MathNet 2019-part-07 — 184 problems (EN–VI) Question 33

Math Olympiad Vault · MathNet 2019-part-07 — 184 problems (EN–VI)

Question 33

Let $k$ be a positive integer. The organising committee of a tennis tournament is to schedule the matches for $2k$ players, where:
(1) every two players play exactly one match against each other;
(2) exactly one match is played each day;
(3) each player checks into the hotel on the day of his first match and leaves the hotel on the day of his last match.
For every day a player stays in the hotel, the organisers must pay $1$ dollar, so the committee wants to minimise the total amount paid to the hotel. Find, with proof, the minimum possible total hotel cost.