Mensa's Most Difficult Maths Tests: Prove your arithmetic prowess by solving the toughest numerical puzzles

Mensa's Most Difficult Number Puzzles: Prove your logical and numerical abilities against...

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

Mensa's Most Difficult IQ Puzzles: Take on the ultimate challenge by solving...

Mensa's Most Difficult Pattern Puzzles: Unleash your creative problem solving to crack...