The Second Scientific American Book of Mathematical Puzzles and Diversions
Martin Gardner
Language: English
Pages: 254
ISBN: 0226282538
Format: PDF / Kindle (mobi) / ePub
"Gardner is often the clown prince of science. . . . His Mathematical Games column in Scientific American is one of the few bridges over C. P. Snow's famous 'gulf of mutual incomprehension' that lies between the technical and literary cultures."—Time
The Second Scientific American Book of Mathematical Puzzles and Diversions
Even More Children's Miscellany: Smart, Silly, and Strange Information That's Essential to Know
Soap Opera Digest (16 May 2016)
written on a slip of paper which is folded and handed to you. Without opening it you pass it on to spectator A. Nine Problems 55 "Open this," you tell him, "and you will find your original three-digit number." Prove that the trick cannot fail to work regardless of the digits chosen by the first spectator. 6. T H E C O L L I D I N G M I S S I L E S Two MISSILES speed directly toward each other, one a t 9,000 miles per hour and the other a t 21,000 miles per hour. They start 1,317 miles apart.
pieces 5, 6 and 7 cannot form the steps to the well. Group competition can be introduced by giving each player a Soma set and seeing who can build a given figure in the shortest length of time. To avoid misinterpretations of these structures i t should be said that the f a r sides of the pyramid and steamer a r e exactly like the near sides; both the hole in the well and the interior of the bathtub have a volume of three cubes; there a r e no holes or projecting pieces on the hidden sides of the
putting five cubes together in all possible ways. Katsanis, in the same letter mentioned above, suggested this and called the pieces "pentacubes." Six pairs of pentacubes a r e mirrorimage forms. If we use only one of each pair, the number of pentacubes drops to 23. Both 29 and 23 a r e primes, therefore no rectangular solids a r e possible with either set. Katsanis proposed a triplication problem: choose one of the 29 pieces, then use 27 of the remaining 28 to form a model of the selected piece,
cannot end in a draw, f o r there a r e nine squares to be captured, but so f a r a s I know it has not been established whether the first or second player has the winning strategy. David Gale, associate professor of mathematics a t Brown University, has devised a delightful dot-connecting game which I shall take the liberty of calling the game of Gale. I t seems on the surface to be similar to the topological game of Hex explained in the first Scientific A m e r i c a n Book of Mathematical
two sets of the plastic pieces so that he \ \ I\\ i /4!3b ------------------A ------------- A pattern FIG. (left) 3. that can be folded into a solid (right), two of which make a tetrahedron. could keep a third piece concealed in his hand. He displays a tetrahedron on the table, then knocks i t over with his hand and a t the same time releases the concealed piece. Naturally his friends do not succeed in forming the tetrahedron out of the three pieces. Concerning the cube I shall mention