Nathan Haselbauer , President of the International High IQ Society, has painstakingly researched and designed this impressively varied collection of over 500 mind-bending Puzzles to enable you to determine just how clever you are.
In theory, each puzzle can be solved - in your head.
Each puzzle is clearly presented, though, and its solution is perfectly clear.
This huge variety of maths, logic and word Puzzles ranges from reasonably straightforward to fiendishly difficult.
Nathan Haselbauer , President of the International High IQ Society, has painstakingly researched and designed this impressively varied collection of over 500 mind-bending Puzzles to enable you to determine just how clever you are