In a Knockout Tournament of 21 teams total match in round one will be :

Question

Accepted Answer

In a knockout tournament, each match eliminates one team, and the tournament continues until only one team remains as the winner. For a tournament with 21 teams, we need to determine how many matches are required in the first round.

1. **Explanation for Option 4 (5 matches):**
   - In a knockout tournament, the number of matches in the first round is typically determined by the need to reduce the number of teams to a power of 2 (e.g., 2, 4, 8, 16, 32, etc.) for subsequent rounds.
   - With 21 teams, the closest power of 2 is 16. To reach 16 teams, we need to eliminate 5 teams in the first round.
   - Therefore, 5 matches are required in the first round to reduce the number of teams from 21 to 16. Each match eliminates one team, so 5 matches will eliminate 5 teams.

2. **Why the other options are incorrect:**
   - **Option 1 (20 matches):** This option suggests that 20 matches are needed in the first round. However, 20 matches would eliminate 20 teams, leaving only 1 team, which is not the goal of the first round.
   - **Option 2 (11 matches):** This option suggests 11 matches, which would eliminate 11 teams, leaving 10 teams. This does not align with the goal of reducing the number to a power of 2.
   - **Option 3 (1 match):** This option suggests only 1 match, which would eliminate just 1 team, leaving 20 teams. This does not sufficiently reduce the number of teams for the next round.

In conclusion, Option 4 is correct because 5 matches are needed in the first round to reduce the number of teams from 21 to 16, allowing the tournament to proceed efficiently in subsequent rounds.