Apr 19 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R6C1 is the only square in row 6 that can be <1>
R6C5 is the only square in row 6 that can be <9>
R6C4 is the only square in row 6 that can be <6>
R7C9 is the only square in row 7 that can be <5>
R9C7 is the only square in row 9 that can be <1>
R9C3 is the only square in row 9 that can be <9>
R3C9 is the only square in block 3 that can be <6>
R2C9 is the only square in column 9 that can be <9>
R4C3 is the only square in block 4 that can be <5>
R7C3 is the only square in column 3 that can be <7>
Intersection of row 2 with block 1. The value <7> only appears in one or more of squares R2C1, R2C2 and R2C3 of row 2. These squares are the ones that intersect with block 1. Thus, the other (non-intersecting) squares of block 1 cannot contain this value.
R3C1 - removing <7> from <23789> leaving <2389>
R3C2 - removing <7> from <357> leaving <35>
R2C2 is the only square in column 2 that can be <7>
R2C7 is the only square in row 2 that can be <5>
Squares R1C3 and R1C7 in row 1 form a simple naked pair. These 2 squares both contain the 2 possibilities <28>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R1C1 - removing <28> from <2489> leaving <49>
R1C5 - removing <2> from <256> leaving <56>
R1C6 - removing <2> from <269> leaving <69>
Intersection of row 6 with block 6. The value <4> only appears in one or more of squares R6C7, R6C8 and R6C9 of row 6. These squares are the ones that intersect with block 6. Thus, the other (non-intersecting) squares of block 6 cannot contain this value.
R4C7 - removing <4> from <2348> leaving <238>
R4C9 - removing <4> from <23478> leaving <2378>
R6C7 is the only square in column 7 that can be <4>
Intersection of row 8 with block 9. The value <8> only appears in one or more of squares R8C7, R8C8 and R8C9 of row 8. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.
R7C8 - removing <8> from <2368> leaving <236>
R8C8 is the only square in column 8 that can be <8>
R8C1 is the only square in row 8 that can be <6>
Intersection of column 9 with block 6. The values <78> only appears in one or more of squares R4C9, R5C9 and R6C9 of column 9. These squares are the ones that intersect with block 6. Thus, the other (non-intersecting) squares of block 6 cannot contain these values.
R4C7 - removing <8> from <238> leaving <23>
Intersection of block 2 with row 3. The values <27> only appears in one or more of squares R3C4, R3C5 and R3C6 of block 2. These squares are the ones that intersect with row 3. Thus, the other (non-intersecting) squares of row 3 cannot contain these values.
R3C1 - removing <2> from <2389> leaving <389>
R3C7 - removing <2> from <238> leaving <38>
Squares R2C1 and R2C8 in row 2 and R7C1 and R7C8 in row 7 form a Simple X-Wing pattern on possibility <3>. All other instances of this possibility in columns 1 and 8 can be removed.
R3C1 - removing <3> from <389> leaving <89>
R4C1 - removing <3> from <378> leaving <78>
R5C1 - removing <3> from <378> leaving <78>
R6C3 is the only square in block 4 that can be <3>
R6C9 can only be <8>
R8C3 can only be <2>
R1C3 can only be <8>
R1C7 can only be <2>
R3C1 can only be <9>
R4C7 can only be <3>
R2C8 can only be <3>
R2C1 can only be <2>
R3C7 can only be <8>
R3C6 can only be <2>
R1C1 can only be <4>
R5C6 can only be <8>
R5C1 can only be <7>
R4C6 can only be <4>
R1C2 can only be <5>
R7C1 can only be <3>
R1C5 can only be <6>
R3C2 can only be <3>
R1C6 can only be <9>
R8C2 can only be <4>
R4C5 can only be <2>
R7C6 can only be <6>
R5C9 can only be <2>
R4C1 can only be <8>
R5C4 can only be <5>
R4C9 can only be <7>
R9C9 can only be <4>
R7C8 can only be <2>
R7C4 can only be <8>
R7C5 can only be <4>
R9C8 can only be <6>
R8C9 can only be <3>
R9C5 can only be <7>
R5C5 can only be <3>
R3C4 can only be <7>
R9C4 can only be <2>
R3C5 can only be <5>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.