The Problem Solved by Changing the Representation

If you try to do it in the regular representation, you have a really hard problem. But this other one is much easier. He gives an example where you have a a chequer board and a so you have 32 tiles that are like one by two rectangle. So each tile can cover two squares,. And you have 32 of these, right? And you can cover the whole board with these 32 tiles, right? They each cover two squares. Ther 64 squares on a chequerBoard. All right. Now, here's the problem. If you remove opposite corners of the chequer board, can you so you'v remove two squares. Can you now tile it with 31 of these