The full reasoning can be found below the Sudoku.
May 03 - Very Hard
Puzzle Copyright © Kevin Stone
Share link:
Reasoning
R2C9 can only be <7>
R3C4 can only be <2>
R2C8 can only be <8>
R3C2 is the only square in row 3 that can be <8>
R5C5 is the only square in row 5 that can be <1>
R3C5 can only be <7>
R3C6 can only be <1>
R1C6 can only be <6>
R1C4 can only be <3>
R1C8 is the only square in row 1 that can be <1>
R8C7 is the only square in row 8 that can be <7>
R7C6 is the only square in row 7 that can be <7>
R9C7 is the only square in row 9 that can be <1>
R7C3 is the only square in row 7 that can be <1>
R4C1 is the only square in column 1 that can be <8>
R1C1 is the only square in column 1 that can be <7>
R5C1 is the only square in column 1 that can be <5>
R5C2 is the only square in row 5 that can be <9>
R1C2 can only be <4>
Squares R2C1 and R8C1 in column 1 form a simple naked pair. These 2 squares both contain the 2 possibilities <23>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R7C1 - removing <23> from <2349> leaving <49>
R9C1 - removing <2> from <249> leaving <49>
R7C7 is the only square in row 7 that can be <3>
R4C2 is the only square in row 4 that can be <3>
R6C3 can only be <2>
R6C2 can only be <7>
R6C6 can only be <8>
R2C3 can only be <3>
R2C1 can only be <2>
R8C1 can only be <3>
R4C8 is the only square in row 4 that can be <7>
R6C9 is the only square in row 6 that can be <3>
R9C4 is the only square in row 9 that can be <8>
Squares R5C9 and R8C9 in column 9 form a simple naked pair. These 2 squares both contain the 2 possibilities <26>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R9C9 - removing <26> from <2456> leaving <45>
Squares R5C8 and R5C9 in block 6 form a simple naked pair. These 2 squares both contain the 2 possibilities <26>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R6C8 - removing <6> from <456> leaving <45>
Intersection of block 8 with row 7. The value <6> 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.
R7C8 - removing <6> from <246> leaving <24>
Squares R1C3, R1C9, R3C3 and R3C9 form a Type-1 Unique Rectangle on <59>.
R3C9 - removing <59> from <459> leaving <4>
R3C7 can only be <5>
R9C9 can only be <5>
R1C9 can only be <9>
R1C3 can only be <5>
R3C3 can only be <9>
R4C7 can only be <4>
R4C5 can only be <2>
R6C8 can only be <5>
R6C4 can only be <6>
R4C6 can only be <9>
R7C5 can only be <6>
R4C4 can only be <5>
R9C6 can only be <2>
R6C5 can only be <4>
R7C4 can only be <9>
R7C1 can only be <4>
R9C2 can only be <6>
R7C8 can only be <2>
R9C1 can only be <9>
R5C8 can only be <6>
R8C9 can only be <6>
R8C2 can only be <2>
R5C9 can only be <2>
R9C8 can only be <4>
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