The World's 200 Hardest Brain Teasers: Mind-Boggling Puzzles, Problems, and Curious Questions to Sharpen Your Brain

by Gary R. Gruber

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. 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).

Genres: Puzzles, Nonfiction, Mathematics

188 pages, Paperback

First published August 1, 2010

Reviews

[Jim]

Just Saying if these were the really the 200 hardest brain teasers I would not be able to solve any of them. I can so this is not literally true...
A reasonably good selection including some I have seen before.
Working on them slowly and probably won't finish the book.

[Annie · Rating 3 out of 5]

Not bad, but not really what I was looking for either.

[Tom Schulte · Rating 4 out of 5]

Lots of good stuff here for what I call (due to Lewis Carroll), "pillow problems" -- stuff I can muse upon and force out the day's cares as I fall asleep. The introductory geometry problem is a monster and I need to revisit it some rainy day.

[lablababla · Rating 3 out of 5]

Not really the hardest, but it does have pretty interesting questions.

[Mangzilla · Rating 4 out of 5]

A good collection of interesting puzzles. No way are they the "Hardest Brain Teasers". The geometric puzzle in the introduction is pretty hard. You can see that it has an answer, but it's hard to find the "proof". The rest are more like the kind you find in a do-it-yourself IQ test.

[lucie parenkyuma · Rating 3 out of 5]

A good way to sharpen the brain despite I felt it was a wee bit exam-like. There are some English vocabulary puzzles as well ,so it's a mix between numbers, triangles and words.