To solve these inventive brainteasers, your brain has to be in tip-top shape. Warm up with some (slightly) easier puzzles: beginning in the left corner of a box with grids, try to reach the bottom right square. You may pass only through the left and right sides of small squares, but not through their top or bottom. And you can't go through the black squares at all. Another challenge involves four dice, all stacked up. Can you find a pattern that lets you figure out how many pips are on the base side? Arrange the "magical dominoes" precisely and mathematically; do the equations to figure out how. There are also unusual card tricks, "cut-it" puzzles that involve reconstructing figures that have been broken up, and three-dimensional conundrums. As you work each one out, you'll feel yourself getting smarter every minute.

WOULD BLETCHLEY PARK--THE TOP-SECRET HOME OF BRITISH WORLD WAR II CODEBREAKERS--HAVE RECRUITED YOU? PUT YOUR MENTAL AGILITY TO THE TEST WITH THESE FIENDISHLY CHALLENGING PUZZLES AND FIND OUT. Have a knack for mastering Morse code? Want to discover whether your crossword hobby might have seen you recruited into the history books? Think you could have contributed to the effort to crack the Nazis' infamous Enigma code? Then this book about Bletchley Park was custom-made for you. When scouring the population for codebreakers, Bletchley Park recruiters left no stone unturned. They devised various ingenious mind-twisters to assess the puzzle-solving capacity of these individuals--hidden codes, cryptic crosswords, secret languages, and complex riddles. These puzzles, together with the fascinating recruitment stories that surround them, are contained in this book, endorsed by Bletchley Park itself. Though they had diverse backgrounds, the codebreakers of Bletchley Park were united in their love of a good puzzle. If you are of the same persuasion, put your intelligence to the test with the mind-boggling puzzles on these pages and ask yourself: Would Bletchley Park have recruited YOU?

Does a glass of ice water filled to the brim overflow when the ice melts? Does the energy inside a sauna increase when you heat it up? What's the best way to cool your coffee—adding the creamer first or last? These and other challenging puzzlers provide a fresh—and fun—approach to learning real physics. Presenting both classic and new problems, Brainteaser Physics challenges readers to use imagination and basic physics principles to find the answers. Göran Grimvall provides detailed and accessible explanations of the solutions, sometimes correcting the standard explanations, sometimes putting a new twist on them. He provides diagrams and equations where appropriate and ends each problem by discussing a specific concept or offering an extra challenge. With Brainteaser Physics, students and veteran physicists alike can sharpen their critical and creative thinking—and have fun at the same time.

What a bargain! At more than 700 puzzle-packed pages, this huge, value-priced collection should keep any solver happy...and busy for a very long time. It contains brain-busting challenges of almost every type: math logic problems for the numerically inclined; absolutely amazing lateral thinking conundrums; really great critical thinking bafflers; and mind-boggling word puzzles. Here's just a small sample of what's inside: The 22nd and 24th presidents of the United States had the same mother and the same father, but were not brothers. How could this be so? Stumped? That's because it's one man--Grover Cleveland--who was reelected after skipping a term. And that's just an easy warm-up!

FLEX YOUR brain power like never before! From acclaimed author Dr. Gary Gruber, whose proven critical-thinking methods have sold more than seven million books, this collection of mind-bending brain teasers is sure to challenge even the most experienced problem solver. Inside are logic puzzles, riddles, maddening math problems, mental games, and more! A ship is twice as old as the ship's boiler was when the ship was as old as the boiler is. The ratio of the boiler's age now to the ship's age now is what? What English word contains all the vowels, in alphabetical order? What is the three-digit number that can be made from the digits 2, 3, 5, and 7 where no two digits in the three-digit number are alike, and where the three-digit number is a multiple of each of the digits chosen? Stumped? Dr. Gruber reveals the fascinating explanations and detailed strategies for solving even the trickiest problems using his exclusive Gruber Method. DISCLAIMER: The brain teasers in this book may get you so wrapped up in critical thinking that you may not be able to do your regular work until you solve them! Any abrupt or gradual increase in creativity, intelligence, or motivation to get a better job suited to your newfound talents is strictly the reader's responsibility. For more than thirty years, Gary R. Gruber, PhD, has been recognized as a leading expert on the SAT, test-taking methods, and critical-thinking skills. His methods have been used by PBS, Sylvan Learning Centers, Grolier's Encyclopedia, and school districts throughout the country. Dr. Gruber's innovative problem-solving strategies make up the heart of the new MyMaxScore's online test prep (www.mymaxscore.com).

Give your brain a workout on the type of brainteasers that challenge the best solvers at the World Puzzle Championships. They're tough, but fun, and the feeling of satisfaction you get when you succeed is simply unbeatable. Some of the puzzles are oldies but goodies, like battleships--and its many variants--where you search for a fleet hidden within a grid. In "Eminent Domain," try to determine which blanks cells are owned by the numbered ones. For "Hex Loops," locate a path that travels through adjacent hexagons: the trick is, it has to end where it started, and the lines can't touch or cross. From Snaky Tiles to Spiral Galaxies, these Mensa-level conundrums will get your mind in shape.

Put your thinking skills to the test with fun and tricky brain teasers for kids 8 to 12 Get ready to flex your mind muscles and think outside the box with The 100 Best Brain Teasers for Kids. You'll follow Ace the alien wizard and their trusty cat Panther as you tackle puzzles and riddles that test your knowledge of wordplay, logic, and math. Will you rescue the Beloved Crystal from the mischievous Flarkspurians and bring peace to Witloo? The quest is yours to complete! 5 levels of play—Explore 100 brain teasers that get tougher as you go, so you stay sharp and improve your creative thinking skills! Clues and answers—Check the Clues section for hints from Panther if you get stuck, and check the Answer Key at the back when you think you've solved the puzzle. Crafty characters—Meet a whole cast of aliens, wizards, and animal friends as you adventure your way through word ladders, logic grids, number formulas, and more! Power up your mind with brain teasers that help you learn new skills and become an intergalactic hero!