User:Vampire Library: Difference between revisions
Jump to navigation
Jump to search
Created page with "I'm not certain of the origins of this puzzle. ==Puzzle== Two friends, Sam and Lloyd, play the following game: each boy, on their turn, removes a number from 1,...,9 without r..." |
No edit summary |
||
| Line 9: | Line 9: | ||
{{Hint| Try to reinterpret the game as taking place on a 3x3 grid.}} | {{Hint| Try to reinterpret the game as taking place on a 3x3 grid.}} | ||
{{Answer| No. At most he can guarantee a draw.}} | {{Answer| No. At most he can guarantee a draw.}} | ||
{{Solution| | {{Solution| This game is actually "equivalent" to Tic Tac Toe on a 3x3 magic square (i.e. each row, column and diagonal sums to 15). Since there is no winning strategy in Tic Tac Toe neither is there for this game.}} | ||
==See also== | ==See also== | ||
[[Category:Game theory]] | [[Category:Game theory]] | ||
Revision as of 18:41, 6 November 2010
I'm not certain of the origins of this puzzle.
Puzzle
Two friends, Sam and Lloyd, play the following game: each boy, on their turn, removes a number from 1,...,9 without replacement. The winner of the game is the one who first obtains 3 numbers that sum to 15. Does Sam have a winning strategy assuming he goes first?
Help
Hint
Try to reinterpret the game as taking place on a 3x3 grid.
Answer
No. At most he can guarantee a draw.
Solution
This game is actually "equivalent" to Tic Tac Toe on a 3x3 magic square (i.e. each row, column and diagonal sums to 15). Since there is no winning strategy in Tic Tac Toe neither is there for this game.