Here’s another little chess puzzle by Martin Gardner, taken from the same paper as earlier.
The task is to place two rooks, two bishops, and two knights on a 4 by 4 chessboard so that no piece attacks any other.
As before, there are two basic solutions, here and here, plus symmetries.
The bishops are on the same coloured squares in both solutions though. Whilst that could come about it still feels like a bit of a cheat.