Killer Sudoku: Killer Sudoku - 200 Hard to Very Hard Puzzles 9x9 (book 23) (Paperback)

Killer Sudoku is a mix of Sudoku and Kakuro. Your goal is the same as in regular sudoku: fill every row, column and 3x3 region with the numbers 1-9 once. The objective is to fill the grid with numbers from 1 to 9 in a way that the following conditions are met: Each row, column, and nonet contains each number exactly once. The sum of all numbers in a cage must match the small number printed in its corner. No number appears more than once in a cage.