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UPSC CSE CSAT 2022 · Question 17 · Counting, permutations & probability

In a tournament of Chess having 150 entrants, a player is eliminated whenever he loses a match. It…

CSAT 2022 · Q17

Counting, permutations & probability Easy

In a tournament of Chess having 150 entrants, a player is eliminated whenever he loses a match. It is given that no match results in a tie/draw. How many matches are played in the entire tournament?

Answer & explanation

Answer: (c) 149

Every match has exactly one loser, and every loser is eliminated. The tournament ends when one player is left, so 149 players are eliminated — and that takes exactly 149 matches.

  1. Each match produces exactly one loser, who is eliminated.
  2. To leave a single winner, 150 − 1 = 149 players must be eliminated.
  3. So 149 matches are played.
  4. Check: with 4 players, 2 semi-finals + 1 final = 3 = 4 − 1 matches.

Remember · Knockout tournament with n players: always n − 1 matches, whatever the byes.

Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·

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