[...]...Contents Introduction Part I ARITHMETIC PUZZLES The Colored Socks Weighty Problem The Silver Bar The Three Cats Mrs PuHem's Cigarettes Part II MONEY PUZZLES Second-Hand Scooter Low Finance No Change AI's Allowance Pick Your Pay Part III SPEED PUZZLES The Bicycles and the Fly The Floating Hat Round Trip Airplane Paradox Part N PLANE GEOMETRY PUZZLES Corner to Corner The Hindu and the Cat Cutting... Square Go? Part V SOLID GEOMETRY PUZZLES Under the Band The Third Line The Painted Cubes The Spotted Basketball vii 1 3 4 6 10 12 13 15 17 19 21 24 25 27 29 31 33 35 37 38 40 43 45 47 49 51 52 Part VI GAME PUZZLES The Circle of Pennies Fox and Goose Bridg-It Nim Part VII PROBABILITY PUZZLES The Three Pennies The Tenth Roll Odds on Kings Boys vs Girls Part VIII TOPOLOGY PUZZLES The Five Bricks Outside... Inside? The Two Knots Reversing the Sweater Part IX MISCELLANEOUS PUZZLES The Five Tetrominoes The Two Tribes No Time for School Time for Toast The Three Neckties Part X TRICKY PUZZLES Suggestions for Further Reading 53 55 57 59 63 65 67 69 71 73 75 77 79 82 85 87 89 92 94 96 98 99 111 PART I '-=lir ~ ~Vc ~ ih·~ ~ - ARITHMETIC PUZZLES Arithmetic Puzzles THE NUMBERS THAT are used in counting (1, 2, 3, 4 ... more smokes; then with the 3 final butts she made one final Cigarette Total: 40 cigarettes Mrs Puffem never smoked again; she failed to recover from the strength of her final puff 12 PART II MONEY PUZZLES Money Puzzles «IF YOU'LL GIVE me your water pistol," says little Tommy to his playmate, .