How to find no of kings using pigeon hole principal

#1

Sir I was doing a problem from mathematical circles and in that book I saw a problem in which we have to find largest no of kings we can place on a chessboard so that no two of them put each other in check.
The ans given in the book is : 12

#2

please read it -

#3

sir i think this article is wrong because question states that no king put other in check and in the solution shown in this article every pair of kings put other kings in check i.e. no king can perform the next move

#4

also the answer given in the book is 12 kings