Solvers looking?for the extreme mental challenge?will find?120 Deadly-level killer puzzles, including, for the first time ever, 20 Extra Deadly,?that?really test their limits: this is the only place they'll find such a torturous collection in a single book. The Times Ultimate Killer Su Doku is not for the faint of heart. The puzzles use the same 9 x 9 grid as Su Doku but?have an added mathematical challenge. The aim is not only to complete every row, column, and cube so that it contains the digits 1?9, it is also necessary to ensure that the outlined cubes add up to the same number as well. But unlike with previous books, there is no chance for solvers?to ease?themselves in with Easy, or even Tough puzzles: this book is the ultimate Killer Su Doku?completely deadly.
