In a grid puzzle, each row and column in the 9x9 grid, as well as each 3 × 3 sub-grid shown with heavy borders, must contain all the digits 1 - 9.
In the above partially filled grid, the square marked “?” contains
1
2
2
3
3
6
4
7
In a grid puzzle, each row and column in the 9x9 grid, as well as each 3 × 3 sub-grid shown with heavy borders, must contain all the digits 1 - 9.
In the above partially filled grid, the square marked “?” contains