title: The World's 200 Hardest Brain Teasers: Mind-Boggling Puzzles, Problems, and Curious Questions to Sharpen Your Brain
author:  Gary Gruber 
description: <strong>Gary R. Gruber, PhD</strong>, is recognized nationally as the leading expert on the SAT, test-taking methods and critical thinking skills. His books on test taking and critical thinking skills have sold more than seven million copies.
zlib_text: The World’s 200 Hardest 
  Brain 
  Teasers
  Mind-Boggling Puzzles, 
  Problems, and 
   Curious Questions to 
  Sharpen Your Brain
  Gary r. GruBer, PhD
  
  Copyright © 2010 by Gary R. Gruber
  Cover and internal design © 2010 by Sourcebooks, Inc.
  Cover design by Larry Nozik/Nozik Design
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  photo.com, Fred-D/iStockphoto.com, emferr/iStockphoto.com
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