Question

Consider a knock-out women's badminton singles tournament where there are no ties. The loser in each game is eliminated from the tournament. Every player plays until she is defeated or remains the last undefeated player. The last undefeated player is declared the winner of the tournament. If there are 64 players in the beginning of the tournament, how many games should be played in total to declare the winner of the tournament?

Choose one option
Official answer and solution
Official answer
C
From
Official GATE 2026 answer key

Solution

Use the invariant that each game in a single-elimination tournament eliminates exactly one player.

In a knock-out tournament with no ties, every game produces exactly one loser who is eliminated from the tournament. Starting with 6464 players, declaring a single undefeated winner requires eliminating 64−1=6364 - 1 = 63 players. Therefore, 6363 games must be played in total (equivalently, 32+16+8+4+2+1=6332 + 16 + 8 + 4 + 2 + 1 = 63).

Final answer

Option (C)

Common trap

Answering 64 instead of 64−1=6364 - 1 = 63.

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

Source

Paper
GATE 2026 Computer Science and Information Technology - Session 1 (CS1)
Question
3 of 65
Section
General Aptitude

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