If you like a good Sudoku try this problem.
Below is an image for a fun problem. Every "cell" (inner white box) is either black or white. The number along the top row give you the total number of black cells in each column. The numbers down the left side of the box gives you the total number of black cells in each row. The numbers in the "L" shape starting on the left give the number in the diagonals in one direction and the rest give you the number in the opposing diagonal direction.
I also included it in the end of my post on Layman's How an X-ray and a CT scan works + fun problem but though I would re-post it for others to enjoy