Dec 05 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R1C7 is the only square in row 1 that can be <1>
R2C8 is the only square in row 2 that can be <8>
R3C6 is the only square in row 3 that can be <8>
R4C3 is the only square in row 4 that can be <1>
R4C7 is the only square in row 4 that can be <9>
R5C5 is the only square in row 5 that can be <1>
R5C1 is the only square in row 5 that can be <5>
R6C7 is the only square in row 6 that can be <3>
R3C9 is the only square in row 3 that can be <3>
R2C2 is the only square in row 2 that can be <3>
R3C7 is the only square in row 3 that can be <5>
R6C6 is the only square in row 6 that can be <6>
R7C1 is the only square in row 7 that can be <1>
R7C3 is the only square in row 7 that can be <8>
R5C2 is the only square in row 5 that can be <8>
R5C3 is the only square in row 5 that can be <4>
R6C3 can only be <2>
R6C4 can only be <4>
R7C7 is the only square in row 7 that can be <4>
R7C5 is the only square in row 7 that can be <6>
R8C9 is the only square in row 8 that can be <5>
R9C5 is the only square in row 9 that can be <3>
R9C2 is the only square in row 9 that can be <4>
R1C5 is the only square in row 1 that can be <4>
R2C1 is the only square in row 2 that can be <4>
Intersection of row 1 with block 1. The value <7> only appears in one or more of squares R1C1, R1C2 and R1C3 of row 1. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.
R3C3 - removing <7> from <679> leaving <69>
Intersection of row 9 with block 9. The value <2> only appears in one or more of squares R9C7, R9C8 and R9C9 of row 9. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.
R7C9 - removing <2> from <279> leaving <79>
R8C8 - removing <2> from <2679> leaving <679>
Intersection of row 7 with block 8. The value <2> only appears in one or more of squares R7C4, R7C5 and R7C6 of row 7. These squares are the ones that intersect with block 8. Thus, the other (non-intersecting) squares of block 8 cannot contain this value.
R8C5 - removing <2> from <279> leaving <79>
Intersection of column 5 with block 2. The value <2> only appears in one or more of squares R1C5, R2C5 and R3C5 of column 5. These squares are the ones that intersect with block 2. Thus, the other (non-intersecting) squares of block 2 cannot contain this value.
R3C4 - removing <2> from <279> leaving <79>
Squares R4C4, R4C6, R7C4 and R7C6 form a Type-1 Unique Rectangle on <27>.
R7C4 - removing <27> from <279> leaving <9>
R7C9 can only be <7>
R3C4 can only be <7>
R8C5 can only be <7>
R7C6 can only be <2>
R5C9 can only be <2>
R8C2 can only be <2>
R4C4 can only be <2>
R4C6 can only be <7>
R5C7 can only be <6>
R2C9 can only be <9>
R8C1 can only be <6>
R1C2 can only be <7>
R1C3 can only be <9>
R1C8 can only be <2>
R3C3 can only be <6>
R9C8 can only be <6>
R2C5 can only be <2>
R3C1 can only be <2>
R9C3 can only be <7>
R5C8 can only be <7>
R9C7 can only be <2>
R8C8 can only be <9>
R3C5 can only be <9>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.