Mensa's Most Difficult Number Puzzles: Prove your logical and numerical abilities against 200 fiendish problems

Mensa Killer Sudoku: More than 200 of the most difficult number puzzles

Mensa's Most Difficult Maths Tests: Prove your arithmetic prowess by solving the...

Mensa Riddles & Conundrums: Over 100 Fiendishly Challenging visual, logic and number...

Mensa: Logic Brainteasers: Tantalize and train your brain with over 200 puzzles