If the probability that two queens, placed at random on a chess board, do not take on each other is `k/207` then find the value of k

If the probability that two queens, placed at random on a chess-board, do not take on each other, is K/207 , then K equals______

If four squares are chosen at random on a chess board, then the probability that they lie in a diagonal line is

There are four letters and four envelopes bearing addresses at random. The probability that the letters are placed in correct envelopes is (K)/(24) , then find the value of K.

(i)If four squares are chosen at random on a chess board, find the probability that they lie on diagonal line. (ii) If two squares are chosen at random on a chess board, what is the Probability that they have exactly on corner in common? (iii) If nine squares are chosen at random on a chess board, what is the probability that they form a square of size 3x3?

If 4 squares are chosen at random on a chess board, the probability that they lie on a diagonal line is

If 4 squares are chosen at random on a chess board,the probability that they lie on a diagonal line is

If 7 squares are chosen at random on a chess board, the probability that they lie on a diagonal line is

If two of the 64 squares are chosen at random on a chess board,the probability that they have a side in common is

If two of the 64 squares are chosen at random on a chess board, the probability that they have a side in common is