Oct 06 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R5C8 can only be <1>
R4C8 can only be <7>
R6C8 can only be <4>
R8C8 can only be <3>
R2C8 can only be <8>
R3C1 is the only square in row 3 that can be <4>
R1C4 is the only square in row 1 that can be <4>
R3C3 is the only square in row 3 that can be <8>
R7C1 is the only square in row 7 that can be <3>
R9C1 is the only square in row 9 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 <6>
R9C3 is the only square in column 3 that can be <2>
R1C7 is the only square in column 7 that can be <5>
R1C9 is the only square in column 9 that can be <3>
Squares R2C2 and R2C4 in row 2 form a simple naked pair. These 2 squares both contain the 2 possibilities <16>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R2C5 - removing <16> from <1367> leaving <37>
R2C6 - removing <1> from <137> leaving <37>
Squares R6C1 and R6C5 in row 6 form a simple naked pair. These 2 squares both contain the 2 possibilities <12>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R6C2 - removing <1> from <159> leaving <59>
R6C9 - removing <2> from <259> leaving <59>
Squares R2C2 and R8C2 in column 2 form a simple naked pair. These 2 squares both contain the 2 possibilities <16>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R4C2 - removing <1> from <189> leaving <89>
Intersection of row 7 with block 9. The value <9> only appears in one or more of squares R7C7, R7C8 and R7C9 of row 7. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.
R9C7 - removing <9> from <179> leaving <17>
R9C9 - removing <9> from <1679> leaving <167>
R7C7 is the only square in column 7 that can be <9>
Intersection of row 8 with block 8. The values <27> only appears in one or more of squares R8C4, R8C5 and R8C6 of row 8. These squares are the ones that intersect with block 8. Thus, the other (non-intersecting) squares of block 8 cannot contain these values.
R9C5 - removing <7> from <1367> leaving <136>
R9C6 - removing <7> from <1379> leaving <139>
Intersection of block 5 with row 5. The value <9> only appears in one or more of squares R5C4, R5C5 and R5C6 of block 5. These squares are the ones that intersect with row 5. Thus, the other (non-intersecting) squares of row 5 cannot contain this value.
R5C2 - removing <9> from <589> leaving <58>
R5C9 - removing <9> from <259> leaving <25>
Intersection of block 5 with column 5. The value <1> only appears in one or more of squares R4C5, R5C5 and R6C5 of block 5. These squares are the ones that intersect with column 5. Thus, the other (non-intersecting) squares of column 5 cannot contain this value.
R1C5 - removing <1> from <168> leaving <68>
R8C5 - removing <1> from <1267> leaving <267>
R9C5 - removing <1> from <136> leaving <36>
Squares R3C7, R3C9, R9C7 and R9C9 form a Type-1 Unique Rectangle on <17>.
R9C9 - removing <17> from <167> leaving <6>
R9C5 can only be <3>
R7C9 can only be <1>
R7C3 can only be <6>
R3C9 can only be <7>
R9C7 can only be <7>
R2C5 can only be <7>
R3C7 can only be <1>
R2C6 can only be <3>
R1C3 can only be <1>
R8C2 can only be <1>
R8C6 can only be <7>
R2C2 can only be <6>
R1C6 can only be <8>
R1C5 can only be <6>
R5C6 can only be <9>
R2C4 can only be <1>
R9C4 can only be <9>
R5C4 can only be <2>
R9C6 can only be <1>
R8C5 can only be <2>
R5C9 can only be <5>
R8C4 can only be <6>
R6C5 can only be <1>
R5C2 can only be <8>
R6C9 can only be <9>
R6C1 can only be <2>
R4C5 can only be <8>
R6C2 can only be <5>
R4C9 can only be <2>
R4C2 can only be <9>
R4C1 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 setting.