Aug 18 - Super Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R7C9 can only be <7>
R7C8 can only be <6>
R8C9 can only be <4>
R9C7 can only be <8>
R3C1 is the only square in row 3 that can be <8>
R1C8 is the only square in row 1 that can be <8>
R1C7 is the only square in row 1 that can be <4>
R1C6 is the only square in row 1 that can be <3>
R3C6 is the only square in row 3 that can be <9>
R1C9 is the only square in row 1 that can be <9>
R5C7 is the only square in row 5 that can be <3>
R6C8 can only be <4>
R6C1 can only be <5>
R4C8 can only be <7>
R2C8 can only be <3>
R5C5 is the only square in row 5 that can be <4>
R5C3 is the only square in row 5 that can be <7>
R6C2 is the only square in row 6 that can be <3>
R6C7 is the only square in row 6 that can be <6>
R9C5 is the only square in column 5 that can be <5>
R8C3 is the only square in row 8 that can be <5>
R4C9 is the only square in column 9 that can be <5>
Squares R2C1 and R8C1 in column 1 form a simple naked pair. These 2 squares both contain the 2 possibilities <67>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the column.
R9C1 - removing <67> from <4679> leaving <49>
Squares R5C4 and R5C6 in block 5 form a simple naked pair. These 2 squares both contain the 2 possibilities <15>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the block.
R4C6 - removing <1> from <128> leaving <28>
R6C4 - removing <1> from <128> leaving <28>
Intersection of row 1 with block 2. The value <7> only appears in one or more of squares R1C4, R1C5 and R1C6 of row 1. These squares are the ones that intersect with block 2. Thus, the other (non-intersecting) squares of block 2 cannot contain this value.
R2C4 - removing <7> from <12567> leaving <1256>
R3C5 - removing <7> from <127> leaving <12>
R1C5 is the only square in column 5 that can be <7>
Squares R5C4, R5C6, R2C4 and R2C6 form a Type-3 Unique Rectangle on <15>. Upon close inspection, it is clear that:
(R2C4 or R2C6)<26> and R1C4<26> form a naked pair on <26> in block 2. No other squares in the block can contain these possibilities
R3C5 - removing <2> from <12> leaving <1>
R7C5 can only be <2>
R9C6 can only be <6>
R8C1 is the only square in row 8 that can be <6>
R2C1 can only be <7>
R3C2 can only be <2>
R3C7 can only be <7>
R1C3 can only be <6>
R1C4 can only be <2>
R6C4 can only be <8>
R2C6 can only be <5>
R2C4 can only be <6>
R5C6 can only be <1>
R5C4 can only be <5>
R8C6 can only be <8>
R6C3 can only be <1>
R4C6 can only be <2>
R4C7 can only be <1>
R4C2 can only be <4>
R2C7 can only be <2>
R6C9 can only be <2>
R7C3 can only be <9>
R2C9 can only be <1>
R7C4 can only be <1>
R4C3 can only be <8>
R9C3 can only be <2>
R9C1 can only be <4>
R8C4 can only be <7>
R8C2 can only be <1>
R9C4 can only be <9>
R9C2 can only be <7>
R4C1 can only be <9>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.