Jul 01 - Very Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R4C4 can only be <3>
R4C6 can only be <5>
R5C1 can only be <9>
R5C3 can only be <5>
R4C1 can only be <6>
R4C9 can only be <9>
R6C1 can only be <3>
R2C2 is the only square in row 2 that can be <5>
R5C5 is the only square in row 5 that can be <2>
R6C9 is the only square in row 6 that can be <6>
R7C2 is the only square in row 7 that can be <3>
R8C9 is the only square in row 8 that can be <5>
R9C5 is the only square in row 9 that can be <5>
R1C4 is the only square in column 4 that can be <2>
R9C6 is the only square in block 8 that can be <7>
Intersection of row 2 with block 3. The value <8> only appears in one or more of squares R2C7, R2C8 and R2C9 of row 2. These squares are the ones that intersect with block 3. Thus, the other (non-intersecting) squares of block 3 cannot contain this value.
R1C9 - removing <8> from <148> leaving <14>
Squares R1C9 and R5C9 in column 9 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 column.
R2C9 - removing <4> from <248> leaving <28>
R9C9 - removing <14> from <1248> leaving <28>
Squares R1C1<147>, R1C5<478>, R1C6<48> and R1C9<14> in row 1 form a comprehensive naked quad. These 4 squares can only contain the 4 possibilities <1478>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R1C2 - removing <4> from <469> leaving <69>
R1C8 - removing <147> from <14679> leaving <69>
Squares R1C2 and R1C8 in row 1 and R9C2 and R9C8 in row 9 form a Simple X-Wing pattern on possibility <9>. All other instances of this possibility in columns 2 and 8 can be removed.
R2C8 - removing <9> from <2479> leaving <247>
R8C2 - removing <9> from <249> leaving <24>
R8C8 - removing <9> from <249> leaving <24>
Squares R8C2 and R8C8 in row 8 form a simple naked pair. These 2 squares both contain the 2 possibilities <24>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R8C1 - removing <24> from <247> leaving <7>
R8C7 - removing <4> from <489> leaving <89>
R1C5 is the only square in row 1 that can be <7>
R3C5 can only be <4>
R7C5 can only be <8>
R1C6 can only be <8>
R7C3 can only be <1>
R9C4 can only be <4>
R6C4 can only be <8>
R6C6 can only be <4>
R3C3 can only be <7>
R9C1 can only be <2>
R9C2 can only be <9>
R9C9 can only be <8>
R2C1 can only be <4>
R8C2 can only be <4>
R9C8 can only be <1>
R1C2 can only be <6>
R8C3 can only be <8>
R2C9 can only be <2>
R8C7 can only be <9>
R1C8 can only be <9>
R3C2 can only be <2>
R2C7 can only be <8>
R1C1 can only be <1>
R2C8 can only be <7>
R3C8 can only be <6>
R2C3 can only be <9>
R3C7 can only be <1>
R7C8 can only be <4>
R7C7 can only be <6>
R8C8 can only be <2>
R1C9 can only be <4>
R5C9 can only be <1>
R5C7 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.