Dec 26 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R4C8 can only be <2>
R6C6 can only be <2>
R4C4 can only be <6>
R4C9 can only be <5>
R5C8 can only be <4>
R5C9 can only be <7>
R2C8 can only be <8>
R1C8 can only be <1>
R4C5 can only be <9>
R6C5 can only be <5>
R9C8 can only be <9>
R7C8 can only be <6>
R7C1 is the only square in row 7 that can be <9>
R6C1 can only be <7>
R6C2 can only be <9>
R7C3 is the only square in row 7 that can be <5>
R8C5 is the only square in row 8 that can be <6>
R9C7 is the only square in row 9 that can be <5>
R8C1 is the only square in column 1 that can be <1>
R2C3 is the only square in column 3 that can be <4>
R2C5 is the only square in row 2 that can be <7>
R7C4 is the only square in row 7 that can be <7>
R9C6 is the only square in column 6 that can be <4>
Squares R1C3 and R1C7 in row 1 form a simple naked pair. These 2 squares both contain the 2 possibilities <27>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R1C1 - removing <2> from <2358> leaving <358>
R1C2 - removing <27> from <25678> leaving <568>
R1C4 - removing <2> from <238> leaving <38>
Squares R1C4 and R5C4 in column 4 form a simple naked pair. These 2 squares both contain the 2 possibilities <38>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R3C4 - removing <38> from <1238> leaving <12>
R9C4 - removing <8> from <128> leaving <12>
Intersection of column 1 with block 1. The values <38> only appears in one or more of squares R1C1, R2C1 and R3C1 of column 1. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain these values.
R1C2 - removing <8> from <568> leaving <56>
R3C2 - removing <8> from <2678> leaving <267>
Intersection of block 2 with row 3. The values <12> only appears in one or more of squares R3C4, R3C5 and R3C6 of block 2. These squares are the ones that intersect with row 3. Thus, the other (non-intersecting) squares of row 3 cannot contain these values.
R3C1 - removing <2> from <238> leaving <38>
R3C2 - removing <2> from <267> leaving <67>
R3C7 - removing <2> from <247> leaving <47>
R3C9 - removing <2> from <234> leaving <34>
Intersection of block 8 with row 7. The value <8> only appears in one or more of squares R7C4, R7C5 and R7C6 of block 8. These squares are the ones that intersect with row 7. Thus, the other (non-intersecting) squares of row 7 cannot contain this value.
R7C9 - removing <8> from <128> leaving <12>
Squares R5C4, R5C6, R1C4 and R1C6 form a Type-1 Unique Rectangle on <38>.
R1C6 - removing <38> from <368> leaving <6>
R1C2 can only be <5>
R5C2 can only be <2>
R5C1 can only be <5>
R8C2 can only be <8>
R9C2 can only be <7>
R9C3 can only be <2>
R3C2 can only be <6>
R9C4 can only be <1>
R1C3 can only be <7>
R9C9 can only be <8>
R3C4 can only be <2>
R7C6 can only be <8>
R1C7 can only be <2>
R8C7 can only be <4>
R2C9 can only be <3>
R2C1 can only be <2>
R3C9 can only be <4>
R3C5 can only be <8>
R3C1 can only be <3>
R7C5 can only be <2>
R1C4 can only be <3>
R3C7 can only be <7>
R8C9 can only be <2>
R7C9 can only be <1>
R5C6 can only be <3>
R1C1 can only be <8>
R5C4 can only be <8>
R3C6 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