More Without Words: Mathematical Puzzles to Confound and Delight James Tanton
* Readers get no clues to what the puzzle is about* They may take hours or even days to work out what is being asked of them* Even after that, some problems may have no solutionThe result - a really challenging book that will fascinate anyone interested in puzzles and recreational mathematicians in particular. This volume contains 36 puz-zles ranging from quite easy to quite difficult.