Welcome back everyone!
Our first puzzle this year was to place 8 queens on a chessboard such that none of the queens could take any of the others. Above is a fail – only 5 queens are on the board and they are no places left to put any more.
Here is H.B.Meyer’s website – try for yourself to fit 8 queens on the board, it is possible!
We then looked at changing the size of the board from an 8 by 8 to smaller sizes, e.g. can you fit 5 queens on a 5 by 5 board? Here is a place to try this. And if so, how many “unique” solutions are there? We defined a unique solution as being one that did not look like any others we had found when we rotated our paper or put it up to the light so it appeared flipped!
There is a great numberphile video on this puzzle, and all the answers for different size boards on wikipedia.