Stretch your mental powers and become an IQ wizard. Stimulating and fun, these logic puzzles, mind-benders, mathematical teasers, and conundrums are a must-have for anyone serious about reaching his or her full potential. And they're compiled by two of MENSA's leading puzzle editors who really know something about giving the brain a workout. Each of the 20 sections contains 25 puzzles; no specialist knowledge is required to answer the questions, and hard and easy ones are randomly mixed. Solve them using standard mathematical or alphabetical calculations. (Some tables up front--including a multiplication table and lists of square, cube, and prime numbers--offer a little extra help for those in need.) Here's an example of just one brain-baffling challenge:

Starting at midnight, snow fell 1 1/2" every 6 hours. If there was already 2 1/4" of snow at midnight, what was the thickness of the snow at 9 o'clock?

So start using that gray matter to its fullest and watch in amazement as your IQ soars to exceptional heights.