A car dealer sells two cars for $9,999 each — one at a 10% profit, the other at a 10% loss. Overall, did the dealer make or lose money? How many common words of six letters can you make from "machine," using each letter only once per word? Raoul asked his brother's wife's mother-in-law's only husband's only daughter to join him and his wife for lunch. What relation is she to Raoul? Decipher hidden quotes, reposition matchsticks to form equilateral triangles, navigate complex mazes, and solve scores of other intriguing challenges with this puzzle treasury. The third in a series of collected brain-teasers, conundrums, and riddles, this volume presents a splendid variety of puzzles created by a dozen renowned mathematicians and puzzle lovers. The 300 original exercises, printed in full color, include 19 different kinds of puzzles, including: 3-D puzzles, chess puzzles, connections, dissections, foldings, geometrical puzzles, logic problems, matchstick puzzles, mazes, moving pieces, number puzzles, put-togethers, strimkos, sudoku, and visual and word challenges. The difficulty level of each puzzle is marked by stars, ranging from 2 to 5; 3 stars indicate an average-level challenge. Complete solutions for every puzzle are included.