Mensa's Most Difficult Number Puzzles Prove Your Logical and Numerical Abilities Against 200 Fiendish Problems

Prove your logical and arithmetical prowess by solving the exceptionally tricky problems in Mensa's Most Difficult Number Puzzles. This full-colour book features a huge variety of numerical conundrums that are certain to test even the most adept of puzzlers. Some puzzles - such as sum skyscraper and calcudoku - will test your mental maths, while others - such as touchy and bridges - will provide a trial for your logical and lateral thinking. Are you up to the fiendish challenge?