PlaySudoku.us
Easy · Puzzle #514
4
8
6
7
8
9
2
1
4
2
3
6
3
5
6
9
4
9
3
8
5
7
3
1
4
7
5
6
2
8
4
8
4
3
5
9
7
6
4
8
7
5
9
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
The pigeonhole principle explains why 8 clues are never enough to guarantee a unique Sudoku solution.
"There is no permanent place in mathematics for ugly mathematics." — G. H. Hardy
"There is no permanent place in mathematics for ugly mathematics." — G. H. Hardy