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#1 2009-10-18 15:43:33

Mayhem
Scratcher
Registered: 2007-05-26
Posts: 1000+

Chessboard/Domino Puzzle.

Take a standard 8x8 chessboard.

Place a marker on two of the corner squares - the must be opposite.  (Eg, top left and bottom right, or top right and bottom left)

Now, take a domino and lay it horizontally or vertically so that it covers 2 squares (a white one and a black one).

Can you cover the whole board with dominoes, without any gaps and without any dominoes overlapping the edge of the board?

*****

Can you explain how you know for certain that it is (or is not) possible?

****

Can you do the same for "chess-boards" of different sizes, eg 3x3, 4x4, 5x5 etc...?


Web-spinning Spider:  http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure:  http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484

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#2 2009-10-18 16:13:23

samurai768
Scratcher
Registered: 2009-07-21
Posts: 1000+

Re: Chessboard/Domino Puzzle.

Mayhem wrote:

Web-spinning Spider:  http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure:  http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484

How did you get 4 lines?
I thought you were only allowed to have two

Last edited by samurai768 (2009-10-18 16:13:41)

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#3 2009-10-18 16:23:37

Mayhem
Scratcher
Registered: 2007-05-26
Posts: 1000+

Re: Chessboard/Domino Puzzle.

samurai768 wrote:

Mayhem wrote:

Web-spinning Spider:  http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure:  http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484

How did you get 4 lines?
I thought you were only allowed to have two

If you solve the puzzle, I'll tell you  big_smile


Web-spinning Spider:  http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure:  http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484

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#4 2009-10-18 16:30:48

djm111
Scratcher
Registered: 2008-10-29
Posts: 1000+

Re: Chessboard/Domino Puzzle.

Mayhem wrote:

Take a standard 8x8 chessboard.

Place a marker on two of the corner squares - the must be opposite.  (Eg, top left and bottom right, or top right and bottom left)

Now, take a domino and lay it horizontally or vertically so that it covers 2 squares (a white one and a black one).

Can you cover the whole board with dominoes, without any gaps and without any dominoes overlapping the edge of the board?

*****

Can you explain how you know for certain that it is (or is not) possible?

****

Can you do the same for "chess-boards" of different sizes, eg 3x3, 4x4, 5x5 etc...?

Do the squares with the corner markers need a counter on them?
EDIT: It isnt possible because the opposite corner squares are the same colour, so when the markers are put on so you cant use them there is an unequal number of black and white squares.

Last edited by djm111 (2009-10-18 16:32:17)


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#5 2009-10-18 16:33:35

Mayhem
Scratcher
Registered: 2007-05-26
Posts: 1000+

Re: Chessboard/Domino Puzzle.

That explanation is true for even grids (4x4, 6x6, 8x8 etc), but not for uneven grids (5x5, 7x7 etc)


Web-spinning Spider:  http://scratch.mit.edu/projects/Mayhem/18456
3D Dungeon Adventure:  http://scratch.mit.edu/projects/Mayhem/23570
Starfighter X: http://scratch.mit.edu/projects/Mayhem/21825
Wandering Knight: http://scratch.mit.edu/projects/Mayhem/28484

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#6 2009-10-18 16:37:35

greenflash
Scratcher
Registered: 2009-05-27
Posts: 1000+

Re: Chessboard/Domino Puzzle.

Uneven works, not even though, b/c the corners are the same color...


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