Problem of the day

Question

Mr. Moves’ class decided to have a chess tournament. If each of the 10 children played each other’s once, how many games were played?

Answer 1

Each child plays nine games. There are a total 10 children. Therefore 10 x 9 = 90 games in total.

Answer 2

Let's line up the 10 children, call them A, B, C, D, E, F, G, H, I, J, K, and L.

A plays first and plays 9 games (the other nine children) and then leaves

B plays next and plays 8 games (the other 8, A has left) and then leaves

C play next and plays 7 games (the other 7, A & B have left) and then leaves the room

Do you see a pattern?

9 + 8 + 7 + 6 + 5 + 4 + 3 + 2 + 1 = ?

Answer 3

10 children played 10 children once -> 10 x 10 = 100 games