Question

How many games must be played when 7 players are in the tournament?

https://courseplayer.avalearning.com/CourseFiles/Questions/809408/Chess.jpg

Answer 1

I think it is 21...

Answer 2

@Here_to_Help15

Answer 3

the equation is An=(n^2-n)/2

Answer 4

This is not well-defined.
We seem to be thinking about a tournament where every possible pair plays once.
2

AB - Done (1)

3

AB
AC
BC - Done (2+1)

4

AB
AC
AD
BD
BD
CD - Done (3+2+1)

5

AB
AC
AD
AE
BC
BD
BE
CD
CE
DE - Done (4+3+2+1)

I think we have it.

\(n \rightarrow \dfrac{n(n-1)}{2}\) -- These are also called "Triangular Numbers".

This is consistent with your result, but you didn't tell us how you arrived at that.

Answer 5

an = an-1 + n - 1

Answer 6

it's 21

Answer 7

I was actually right lol Thank you everyone!!

Answer 8

you are welcome:)