Question

In an 8x8 chess, how many ways to put 2 rocks, with no shared rows or columns?

Answer 1

there are 1568 ways to keep roofs in such a way that they do not share row or column.

first rook can be placed in 64 ways n now 2 rook has only 7 rows n 7 columns to be placed
so, 64 ×7×7/2
= 1568