Jan 14 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R1C9 can only be <7>
R2C5 can only be <4>
R9C9 can only be <4>
R3C8 can only be <3>
R2C8 can only be <2>
R2C7 can only be <5>
R2C2 can only be <3>
R2C3 can only be <1>
R3C7 can only be <8>
R1C1 can only be <9>
R9C1 can only be <8>
R4C4 is the only square in row 4 that can be <4>
R4C6 is the only square in row 4 that can be <5>
R1C6 can only be <3>
R1C4 can only be <5>
R4C1 is the only square in row 4 that can be <3>
R6C1 can only be <6>
R6C9 can only be <2>
R6C3 can only be <9>
R4C9 can only be <6>
R4C3 can only be <2>
R5C2 can only be <8>
R5C6 is the only square in row 5 that can be <2>
R6C4 is the only square in row 6 that can be <3>
R7C3 is the only square in row 7 that can be <4>
R7C6 is the only square in row 7 that can be <8>
R6C5 is the only square in row 6 that can be <8>
R8C7 is the only square in row 8 that can be <3>
Squares R9C4 and R9C6 in block 8 form a simple naked pair. These 2 squares both contain the 2 possibilities <19>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R7C4 - removing <19> from <1679> leaving <67>
R8C5 - removing <9> from <679> leaving <67>
Intersection of column 5 with block 5. The value <9> only appears in one or more of squares R4C5, R5C5 and R6C5 of column 5. These squares are the ones that intersect with block 5. Thus, the other (non-intersecting) squares of block 5 cannot contain this value.
R5C4 - removing <9> from <169> leaving <16>
Intersection of column 8 with block 9. The value <7> only appears in one or more of squares R7C8, R8C8 and R9C8 of column 8. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.
R7C7 - removing <7> from <179> leaving <19>
Squares R3C2, R3C3, R8C2 and R8C3 form a Type-1 Unique Rectangle on <56>.
R8C2 - removing <56> from <569> leaving <9>
R8C8 can only be <7>
R7C2 can only be <6>
R8C5 can only be <6>
R7C4 can only be <7>
R3C2 can only be <5>
R8C3 can only be <5>
R3C4 can only be <9>
R3C3 can only be <6>
R5C5 can only be <9>
R3C6 can only be <7>
R9C4 can only be <1>
R6C6 can only be <1>
R5C8 can only be <1>
R4C5 can only be <7>
R5C4 can only be <6>
R7C8 can only be <9>
R6C7 can only be <7>
R9C6 can only be <9>
R4C7 can only be <9>
R7C7 can only be <1>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode option – I recommend not using your browser's dark mode or extensions for BrainBashers