Hard sudoku — printable sheet 18
Four hard puzzles, one page. Answer key: view answers.
3
5
2
9
6
8
1
7
2
1
9
7
6
9
4
4
8
9
1
6
9
2
1
6
1
4
7
8
4
7
6
5
7
4
2
6
1
2
5
4
8
7
9
3
2
7
8
3
6
6
1
8
2
2
9
4
1
1
2
6
9
3
4
8
6
9
8
3
4
7
5
1
8
1
9
9
2
6
1
7
1
2
5
5
8
7
1
2
3
1
4
5
4
1
3
8
4
5
7
7
8
1
9
2
1
7
4
5
6
Sheet 18 of 20 · all hard sheets