[Chess boards and chess pieces]

What is the maximum number of kings that can be placed on a chessboard so that no two of them attack each other

#
A chessboard can be divided into 16 squares of $2 \times 2$. No more than one king can be placed in each of them.

On the other hand, one king can be placed in each: for example, in the upper left corners of each of these squares.

## Answer

16 kings.