ReasoningAges 13-15

Round-robin & network connections

Use n(n − 1) ÷ 2 to count the total number of unique pairwise connections or games in a group. Review suitability for your learners before teaching.

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Age band:Ages 10-12 Ages 13-15

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Worksheet StudioPractice pack · Ages 13-15

Round-robin & network connections

Take your time. Show your thinking.

1. In a round-robin tournament with 28 players, every player plays every other player exactly once. How many games are played in total?
28 · Round-robin & network conn…
2. In a round-robin tournament with 7 players, every player plays every other player exactly once. How many games are played in total?
7 · Round-robin & network conn…
3. In a round-robin tournament with 9 players, every player plays every other player exactly once. How many games are played in total?
9 · Round-robin & network conn…
4. In a round-robin tournament with 16 players, every player plays every other player exactly once. How many games are played in total?
16 · Round-robin & network conn…
5. In a round-robin tournament with 19 players, every player plays every other player exactly once. How many games are played in total?
19 · Round-robin & network conn…
6. In a round-robin tournament with 14 players, every player plays every other player exactly once. How many games are played in total?
14 · Round-robin & network conn…
7. In a round-robin tournament with 30 players, every player plays every other player exactly once. How many games are played in total?
30 · Round-robin & network conn…
8. In a round-robin tournament with 4 players, every player plays every other player exactly once. How many games are played in total?
4 · Round-robin & network conn…
9. In a round-robin tournament with 25 players, every player plays every other player exactly once. How many games are played in total?
25 · Round-robin & network conn…
10. In a round-robin tournament with 20 players, every player plays every other player exactly once. How many games are played in total?
20 · Round-robin & network conn…
11. In a round-robin tournament with 5 players, every player plays every other player exactly once. How many games are played in total?
5 · Round-robin & network conn…
12. In a round-robin tournament with 15 players, every player plays every other player exactly once. How many games are played in total?
15 · Round-robin & network conn…

12 questions · Seed 104730 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 13-15

Round-robin & network connections

Answers and reasoning. Review before teaching.

1. In a round-robin tournament with 28 players, every player plays every other player exactly once. How many games are played in total?
378
Each of the 28 players plays 27 others, and dividing by 2 avoids double-counting: (28 × 27) ÷ 2 = 378 games.
2. In a round-robin tournament with 7 players, every player plays every other player exactly once. How many games are played in total?
21
Each of the 7 players plays 6 others, and dividing by 2 avoids double-counting: (7 × 6) ÷ 2 = 21 games.
3. In a round-robin tournament with 9 players, every player plays every other player exactly once. How many games are played in total?
36
Each of the 9 players plays 8 others, and dividing by 2 avoids double-counting: (9 × 8) ÷ 2 = 36 games.
4. In a round-robin tournament with 16 players, every player plays every other player exactly once. How many games are played in total?
120
Each of the 16 players plays 15 others, and dividing by 2 avoids double-counting: (16 × 15) ÷ 2 = 120 games.
5. In a round-robin tournament with 19 players, every player plays every other player exactly once. How many games are played in total?
171
Each of the 19 players plays 18 others, and dividing by 2 avoids double-counting: (19 × 18) ÷ 2 = 171 games.
6. In a round-robin tournament with 14 players, every player plays every other player exactly once. How many games are played in total?
91
Each of the 14 players plays 13 others, and dividing by 2 avoids double-counting: (14 × 13) ÷ 2 = 91 games.
7. In a round-robin tournament with 30 players, every player plays every other player exactly once. How many games are played in total?
435
Each of the 30 players plays 29 others, and dividing by 2 avoids double-counting: (30 × 29) ÷ 2 = 435 games.
8. In a round-robin tournament with 4 players, every player plays every other player exactly once. How many games are played in total?
6
Each of the 4 players plays 3 others, and dividing by 2 avoids double-counting: (4 × 3) ÷ 2 = 6 games.
9. In a round-robin tournament with 25 players, every player plays every other player exactly once. How many games are played in total?
300
Each of the 25 players plays 24 others, and dividing by 2 avoids double-counting: (25 × 24) ÷ 2 = 300 games.
10. In a round-robin tournament with 20 players, every player plays every other player exactly once. How many games are played in total?
190
Each of the 20 players plays 19 others, and dividing by 2 avoids double-counting: (20 × 19) ÷ 2 = 190 games.
11. In a round-robin tournament with 5 players, every player plays every other player exactly once. How many games are played in total?
10
Each of the 5 players plays 4 others, and dividing by 2 avoids double-counting: (5 × 4) ÷ 2 = 10 games.
12. In a round-robin tournament with 15 players, every player plays every other player exactly once. How many games are played in total?
105
Each of the 15 players plays 14 others, and dividing by 2 avoids double-counting: (15 × 14) ÷ 2 = 105 games.

12 questions · Seed 104730 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 13-15

Round-robin & network connections

Take your time. Show your thinking.

1. In a round-robin tournament with 28 players, every player plays every other player exactly once. How many games are played in total?
28 · Round-robin & network conn…
2. In a round-robin tournament with 7 players, every player plays every other player exactly once. How many games are played in total?
7 · Round-robin & network conn…
3. In a round-robin tournament with 9 players, every player plays every other player exactly once. How many games are played in total?
9 · Round-robin & network conn…
4. In a round-robin tournament with 16 players, every player plays every other player exactly once. How many games are played in total?
16 · Round-robin & network conn…
5. In a round-robin tournament with 19 players, every player plays every other player exactly once. How many games are played in total?
19 · Round-robin & network conn…
6. In a round-robin tournament with 14 players, every player plays every other player exactly once. How many games are played in total?
14 · Round-robin & network conn…
7. In a round-robin tournament with 30 players, every player plays every other player exactly once. How many games are played in total?
30 · Round-robin & network conn…
8. In a round-robin tournament with 4 players, every player plays every other player exactly once. How many games are played in total?
4 · Round-robin & network conn…
9. In a round-robin tournament with 25 players, every player plays every other player exactly once. How many games are played in total?
25 · Round-robin & network conn…
10. In a round-robin tournament with 20 players, every player plays every other player exactly once. How many games are played in total?
20 · Round-robin & network conn…
11. In a round-robin tournament with 5 players, every player plays every other player exactly once. How many games are played in total?
5 · Round-robin & network conn…
12. In a round-robin tournament with 15 players, every player plays every other player exactly once. How many games are played in total?
15 · Round-robin & network conn…

12 questions · Seed 104730 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 13-15

Round-robin & network connections

Answers and reasoning. Review before teaching.

1. In a round-robin tournament with 28 players, every player plays every other player exactly once. How many games are played in total?
378
Each of the 28 players plays 27 others, and dividing by 2 avoids double-counting: (28 × 27) ÷ 2 = 378 games.
2. In a round-robin tournament with 7 players, every player plays every other player exactly once. How many games are played in total?
21
Each of the 7 players plays 6 others, and dividing by 2 avoids double-counting: (7 × 6) ÷ 2 = 21 games.
3. In a round-robin tournament with 9 players, every player plays every other player exactly once. How many games are played in total?
36
Each of the 9 players plays 8 others, and dividing by 2 avoids double-counting: (9 × 8) ÷ 2 = 36 games.
4. In a round-robin tournament with 16 players, every player plays every other player exactly once. How many games are played in total?
120
Each of the 16 players plays 15 others, and dividing by 2 avoids double-counting: (16 × 15) ÷ 2 = 120 games.
5. In a round-robin tournament with 19 players, every player plays every other player exactly once. How many games are played in total?
171
Each of the 19 players plays 18 others, and dividing by 2 avoids double-counting: (19 × 18) ÷ 2 = 171 games.
6. In a round-robin tournament with 14 players, every player plays every other player exactly once. How many games are played in total?
91
Each of the 14 players plays 13 others, and dividing by 2 avoids double-counting: (14 × 13) ÷ 2 = 91 games.
7. In a round-robin tournament with 30 players, every player plays every other player exactly once. How many games are played in total?
435
Each of the 30 players plays 29 others, and dividing by 2 avoids double-counting: (30 × 29) ÷ 2 = 435 games.
8. In a round-robin tournament with 4 players, every player plays every other player exactly once. How many games are played in total?
6
Each of the 4 players plays 3 others, and dividing by 2 avoids double-counting: (4 × 3) ÷ 2 = 6 games.
9. In a round-robin tournament with 25 players, every player plays every other player exactly once. How many games are played in total?
300
Each of the 25 players plays 24 others, and dividing by 2 avoids double-counting: (25 × 24) ÷ 2 = 300 games.
10. In a round-robin tournament with 20 players, every player plays every other player exactly once. How many games are played in total?
190
Each of the 20 players plays 19 others, and dividing by 2 avoids double-counting: (20 × 19) ÷ 2 = 190 games.
11. In a round-robin tournament with 5 players, every player plays every other player exactly once. How many games are played in total?
10
Each of the 5 players plays 4 others, and dividing by 2 avoids double-counting: (5 × 4) ÷ 2 = 10 games.
12. In a round-robin tournament with 15 players, every player plays every other player exactly once. How many games are played in total?
105
Each of the 15 players plays 14 others, and dividing by 2 avoids double-counting: (15 × 14) ÷ 2 = 105 games.

12 questions · Seed 104730 · Age guidance, not curriculum certification