Two players play this game. Numbers from 1 to 9 are layed out in a row. Players take turns putting a coin on one of the numbers that does not yet have a coin on it. Player one puts his coins head-up, and player two -- tails-up.

The winner of this game is the first person to have their coins on three numbers that add up to 15. (For example if a player has coins on 1, 6 and 9, they can win the game by putting a coin on either 8 or 5.)

Is there a strategy for playing this game? Is there a sure-fire way of winning?

First, construct a Magic Square:

8 1 6
3 5 7
4 9 2

Now the game is identical to Tic-Tac-Toe, and so is the strategy: in a well played game, neither player will win.

Posted by TomM on 2002-05-10 18:21:34