Three different squares are chosen randomly on a chessboard.

What is the probability that they lie in the same diagonal?

(In reply to

Simple solution (no program used) by Penny)

Penny, you wrote:

*"So the odds that all three are on the same diagonal, are:
*

(28/64)*(7/63)*(7/62) + (20/64)*(9/63)*(9/62) + (12/64)*(11/63)*(11/62) + (4/64)*(13/63)*(13/62)

= 0.0204813108"

I don't understand how you came up with these odds, but they seem incorrect.