Jul 04 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R1C1 is the only square in row 1 that can be <6>
R5C1 can only be <8>
R9C1 can only be <1>
R2C7 is the only square in row 2 that can be <2>
R3C5 is the only square in row 3 that can be <8>
R4C9 is the only square in row 4 that can be <3>
R4C4 is the only square in row 4 that can be <8>
R4C5 is the only square in row 4 that can be <9>
R5C6 is the only square in row 5 that can be <2>
R6C8 is the only square in row 6 that can be <9>
R7C4 is the only square in row 7 that can be <3>
R8C8 is the only square in row 8 that can be <2>
R8C1 is the only square in row 8 that can be <9>
R3C2 is the only square in row 3 that can be <9>
R2C9 is the only square in row 2 that can be <9>
R9C9 is the only square in row 9 that can be <5>
R9C3 is the only square in row 9 that can be <8>
R2C2 is the only square in column 2 that can be <1>
R8C7 is the only square in column 7 that can be <6>
R6C6 is the only square in column 6 that can be <6>
R5C2 is the only square in row 5 that can be <6>
R7C3 is the only square in row 7 that can be <6>
R9C4 is the only square in row 9 that can be <6>
R1C9 is the only square in column 9 that can be <7>
Squares R7C8 and R7C9 in row 7 form a simple naked pair. These 2 squares both contain the 2 possibilities <14>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R7C2 - removing <4> from <247> leaving <27>
R7C5 - removing <14> from <1247> leaving <27>
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.
R1C6 - removing <5> from <1345> leaving <134>
Intersection of row 6 with block 5. The value <1> only appears in one or more of squares R6C4, R6C5 and R6C6 of row 6. These squares are the ones that intersect with block 5. Thus, the other (non-intersecting) squares of block 5 cannot contain this value.
R5C4 - removing <1> from <145> leaving <45>
Intersection of column 7 with block 3. The value <1> only appears in one or more of squares R1C7, R2C7 and R3C7 of column 7. These squares are the ones that intersect with block 3. Thus, the other (non-intersecting) squares of block 3 cannot contain this value.
R1C8 - removing <1> from <1345> leaving <345>
R3C8 - removing <1> from <134> leaving <34>
Squares R7C8, R7C9, R5C8 and R5C9 form a Type-1 Unique Rectangle on <14>.
R5C8 - removing <14> from <145> leaving <5>
R5C4 can only be <4>
R4C7 can only be <4>
R4C2 can only be <7>
R3C7 can only be <1>
R5C9 can only be <1>
R7C9 can only be <4>
R7C8 can only be <1>
R1C7 can only be <5>
R4C6 can only be <5>
R7C2 can only be <2>
R6C1 can only be <3>
R6C3 can only be <4>
R3C1 can only be <7>
R8C3 can only be <7>
R7C5 can only be <7>
R9C2 can only be <4>
R6C5 can only be <1>
R8C4 can only be <1>
R2C3 can only be <3>
R8C6 can only be <4>
R6C4 can only be <7>
R9C5 can only be <2>
R2C6 can only be <7>
R2C4 can only be <5>
R3C6 can only be <3>
R3C8 can only be <4>
R1C6 can only be <1>
R1C8 can only be <3>
R1C5 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 setting.