Oct 15 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R7C9 can only be <5>
R9C9 can only be <1>
R3C9 can only be <2>
R1C9 can only be <8>
R4C7 is the only square in row 4 that can be <2>
R5C7 is the only square in row 5 that can be <8>
R7C6 is the only square in row 7 that can be <8>
R7C3 is the only square in row 7 that can be <4>
R2C3 is the only square in column 3 that can be <2>
R8C7 is the only square in column 7 that can be <9>
Squares R1C2 and R1C8 in row 1 form a simple naked pair. These 2 squares both contain the 2 possibilities <36>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R1C1 - removing <3> from <39> leaving <9>
R1C4 - removing <36> from <23679> leaving <279>
R1C5 - removing <36> from <34679> leaving <479>
R1C6 - removing <6> from <24679> leaving <2479>
Squares R4C5 and R6C5 in column 5 form a simple naked pair. These 2 squares both contain the 2 possibilities <79>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R1C5 - removing <7> from <47> leaving <4>
R8C5 - removing <7> from <4567> leaving <456>
R9C5 - removing <79> from <35679> leaving <356>
R8C6 is the only square in row 8 that can be <4>
Squares R4C5 and R6C5 in block 5 form a simple naked pair. These 2 squares both contain the 2 possibilities <79>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R5C4 - removing <7> from <167> leaving <16>
R5C6 - removing <7> from <167> leaving <16>
Squares R2C6 and R5C6 in column 6 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.
R3C6 - removing <16> from <169> leaving <9>
R9C6 - removing <6> from <2679> leaving <279>
R9C4 is the only square in row 9 that can be <9>
R9C6 is the only square in row 9 that can be <2>
R1C6 can only be <7>
R1C4 can only be <2>
Intersection of row 2 with block 2. The value <5> only appears in one or more of squares R2C4, R2C5 and R2C6 of row 2. 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 <5> from <1356> leaving <136>
Intersection of column 1 with block 7. The value <7> only appears in one or more of squares R7C1, R8C1 and R9C1 of column 1. These squares are the ones that intersect with block 7. Thus, the other (non-intersecting) squares of block 7 cannot contain this value.
R8C3 - removing <7> from <567> leaving <56>
R8C4 is the only square in row 8 that can be <7>
R2C4 is the only square in column 4 that can be <5>
Squares R1C2 and R9C2 in column 2 and R1C8 and R9C8 in column 8 form a Simple X-Wing pattern on possibility <6>. All other instances of this possibility in rows 1 and 9 can be removed.
R9C5 - removing <6> from <356> leaving <35>
Squares R4C3, R4C5, R6C3 and R6C5 form a Type-1 Unique Rectangle on <79>.
R6C3 - removing <79> from <379> leaving <3>
R6C7 can only be <7>
R5C2 can only be <5>
R6C5 can only be <9>
R7C7 can only be <6>
R5C8 can only be <3>
R7C4 can only be <3>
R9C8 can only be <7>
R5C3 can only be <7>
R4C3 can only be <9>
R1C8 can only be <6>
R4C5 can only be <7>
R7C1 can only be <7>
R9C5 can only be <5>
R9C1 can only be <3>
R8C5 can only be <6>
R1C2 can only be <3>
R8C3 can only be <5>
R2C5 can only be <3>
R9C2 can only be <6>
R3C1 can only be <5>
R2C7 can only be <1>
R2C6 can only be <6>
R3C7 can only be <3>
R3C3 can only be <6>
R3C4 can only be <1>
R5C4 can only be <6>
R5C6 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.