Rooks Under Siege

On a 8 by 8 chessboard, 2 rooks are randomly placed on 2 different squares of the chessboard. The probability that these 2 rooks will be able to attack each other has the form ab \frac {a} {b} , where a a and bb are coprime. What is a+b a + b?

Note: Rooks can attack anywhere along the row and column they are in.

×

Problem Loading...

Note Loading...

Set Loading...