Mensa Presents Number Puzzles for Math Geniuses: 200 Fiendish and Intriguing Mind Games

Pit your wits against the number crunchers at Mensa Publications who have devised this demonic collection of over 200 mind-boggling number puzzles.

These are fun puzzles, but they are by no means easy. If you can solve them, you'll be a candidate for Mensa -- the internationally famous high-IQ society!