This is a collection of arithmetical puzzles which operate by substituting letters for numbers. The author clearly explains how to solve them, and they range from easy to very complex.
Challenge yourself with over 100 fresh paradoxes, puzzles, riddles, conundrums, word and number games for the jaded, skeptical puzzlist. Over 100 pages of comprehensive answers. Approximately 300 illustrations. "Excellent collection of unusual, offbeat, and completely original puzzles."—Scientific American.
More than 60 new puzzles and stunts based on the properties of numbers. Easy techniques for multiplying large numbers mentally, identifying unknown numbers, determining the date of any day in any year, interest rates worked in one’s head; such entertainments as The Lost Digit, and Psychic Bridge; over 30 pages of magic squares, triangles, cubes, much more. Inexhaustible source of stimulating mathematical recreation. 76 illustrations.
Caliban's Problem Book: Mathematical, Inferential and Cryptographic Puzzles
A small chapter is devoted to logic puzzles and the solutions are included. The authors were two of the leading figures in recreational mathematics in the sixties. Joseph Madachy was the founder of Recreational Mathematics Magazine and the editor of Journal of Recreational Mathematics for nearly thirty years
