Question

In how many ways is it possible to choose a white square and a black square on a chessboards, so that the squares must not lie in the same row or column?

• A. $56$
• B. $896$
• C. $60$
• D. $768$

Answer 1

The correct option is D $768$

In a chess board $32$ white squares are there and $32$ black.

If we choose $32$ white squares there will be $8$ of black square lying in same row or column of that white square.

So, for each white square we have $24$ choice.

$\therefore$ Overall $=32\times 24=768.$

Hence, the answer is $768.$