7. THREE-SQUARE PUZZLE.
Cut seventeen slips of cardboard of equal lengths, and place them on a table to form six squares, as in the [diagram]. It is now required to take away five of the pieces, yet to leave but three perfect squares.
8. CYLINDER PUZZLE.
Cut a piece of cardboard about four inches long, of the shape of the [diagram], and make three holes in it as represented. The puzzle is, to make one piece of wood pass through, and also exactly to fill, each of the three holes.
9. THE NUNS.
Twenty-four nuns were arranged in a convent by night by a sister, to count nine each way, as in the [diagram]. Four of them went out for a walk by moonlight. How were the remainder placed in the square so as still to count nine each way? The four who went out returned, bringing with them four friends; how were they all placed still to count nine each way, and thus to deceive the sister, as to whether there were 20, 24, 28, or 32, in the square?