







Four dots are randomly placed on an 8x8 grid 
20100226 

bobbym pose la question : Four dots are randomly placed on an 8x8 grid, compute the probability
that no row or column contains more than one dot. Claude Tardif lui répond. 





Grain of rice on a chess board 
20090330 

andy pose la question : Is there an easy way for my students to find out 8 to the power of 21 to solve the grains of rice doubling investigation on a chessboard? Any suggestions welcome. Thanks very much Robert Dawson and Claude Tardif lui répond. 





The board for a variant of chess 
20090316 

Adam pose la question : I am trying to figure out how big a piece of wood I need for a variant of chess I thought up. The board essentially is a set of 6 concentric rings with an empty space in the center, each ring consisting of 24 spaces  so essentially 6 concentric 24sided polygonal rings made up of trapezoidal spaces. I know the interior angle of the shape (15 degrees), but I can't figure out the size this thing should be.
All I know is that the innermost ring will have the smallest spaces, and that those spaces need to be able to accommodate chess pieces 3/4" wide without them overlapping onto neighboring spaces. That is to say, the short parallel side of the trapezoidal space on the innermost ring should be at least 3/4". But I have no clue how to extrapolate the full diameter of the board from that one measurement. HELP!
Adam Goss
saganth@yahoo.com Stephen La Rocque lui répond. 





How many squares are there on a checkerboard 
20061217 

Tania pose la question : how many squares are there altogether on the checkerboard (including the 64 small squares)? Penny Nom lui répond. 





Tiffany plays first board for her middle school chess team 
20021202 

Patty pose la question : Tiffany plays first board for her middle school chess team. Since she joined the team last year, she has won 27 of 51 tournament games. That's a winning percentage of about 53%. If Tiffany went on a winning streak, how many games would she need to win in a row to raise her winning percentage to 60% Use variables and equations to communicate the method you've used to solve the problem. Penny Nom lui répond. 





Squares on a chess board 
20010411 

Tom pose la question : It was once claimed that there are 204 squares on an ordinary chessboard (8sq. x 8sq.) Can you justify this claim? "PLEASE" include pictures. How many rectangles are there on an ordinary chessboard? (8sq. x 8sq.) "PLEASE" include pictures. Penny Nom lui répond. 





8 Queens on a Chess Board 
20000606 

Patrick McGarrity pose la question : In the classic puzzle where you put 8 Queens on a chess board and no queen can take any other queen, I was wondering if there was multiple solutions. Obviously there's the mirror and opposite images of the way I solved it, but I was wondering how many solutions there were, and if these solutions all followed a similar pattern? Claude Tardif lui répond. 





How many squares are on a chessboard? 
19991020 

Tchilco pose la question : How many squares are on a chessboard? Penny Nom and Claude Tardif lui répond. 

