Question

Every evening for the months of September and October, the following eight Gry ndor students, Harry, Ron, Hermione, Ginny, Fred, George, Seamus, and Dean will play a game of Exploding Snap. Let's suppose that each night, exactly three of them play one game. Can there be a game of Exploding Snap every evening throughout September and October without having the same three Gry ndors play a game twice

Answer 1

Yes. There can be 56 games (92%) of Exploding Snap every evening throughout September and October that can be played without having the same three Gry ndors play a game twice.

Explanation:

This is a combination game without repetition.

The formula for combination without repetition is:

n! /r! (n - r)!

where n = 8 and r = 3

Therefore, n! /r! (n - r)!

= 8! / 3! (8 -3)!

= 40,320 / 6 (120)

= 40,320 / 720

= 56

There are 30 nights in September and 31 nights in October, totaling 61 nights

This implies that 56/61 games can be played in these two months without repeating the same three gamers.

56/61 = 0.918

= 92%