The Times Killer Su Doku 3: 150 challenging puzzles from The Times (The Times Su Doku) by The Times Mind Games
Push your nerve and logic to the absolute limit with this third collection of The Times Killer Su Doku.
The puzzles use the same 9x9 grid as normal Su Doku but with an added mathmatical 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.
With 150 new Killer Su Doku puzzles, you can ease yourself in with the Moderate before taking the plunge and tackling the real killers:
20 Moderate
50 Tricky
50 Tough
30 Deadly
For those who like to live dangerously and push beyond their mental comfort zone, steel yourself for The Times' toughest collection yet.