Aug 24 - Hard
Puzzle Copyright © Kevin Stone
Share link – www.brainbashers.com
Reasoning
R5C5 can only be <9>
R4C4 can only be <2>
R6C6 can only be <4>
R3C7 is the only square in row 3 that can be <9>
R4C1 is the only square in row 4 that can be <9>
R5C8 is the only square in row 5 that can be <4>
R2C9 is the only square in row 2 that can be <4>
R3C4 is the only square in row 3 that can be <4>
R9C3 is the only square in row 9 that can be <4>
R9C2 is the only square in row 9 that can be <9>
R8C4 is the only square in row 8 that can be <9>
R1C9 is the only square in column 9 that can be <8>
R2C5 is the only square in row 2 that can be <8>
R5C3 is the only square in block 4 that can be <3>
Intersection of row 9 with block 9. The value <8> only appears in one or more of squares R9C7, R9C8 and R9C9 of row 9. These squares are the ones that intersect with block 9. Thus, the other (non-intersecting) squares of block 9 cannot contain this value.
R7C7 - removing <8> from <23568> leaving <2356>
R7C8 - removing <8> from <23568> leaving <2356>
Intersection of column 1 with block 7. The values <35> 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 these values.
R7C2 - removing <5> from <125678> leaving <12678>
R8C2 - removing <5> from <1256> leaving <126>
Intersection of block 2 with row 1. The value <6> only appears in one or more of squares R1C4, R1C5 and R1C6 of block 2. These squares are the ones that intersect with row 1. Thus, the other (non-intersecting) squares of row 1 cannot contain this value.
R1C2 - removing <6> from <12567> leaving <1257>
R1C3 - removing <6> from <1267> leaving <127>
R1C7 - removing <6> from <23567> leaving <2357>
R1C8 - removing <6> from <12356> leaving <1235>
Intersection of block 4 with column 2. The value <2> only appears in one or more of squares R4C2, R5C2 and R6C2 of block 4. These squares are the ones that intersect with column 2. Thus, the other (non-intersecting) squares of column 2 cannot contain this value.
R1C2 - removing <2> from <1257> leaving <157>
R7C2 - removing <2> from <12678> leaving <1678>
R8C2 - removing <2> from <126> leaving <16>
Squares R7C1<2356>, R7C4<36>, R7C7<2356> and R7C8<2356> in row 7 form a comprehensive naked quad. These 4 squares can only contain the 4 possibilities <2356>. Since each of the squares must contain one of the possibilities, they can be eliminated from the other squares in the row.
R7C2 - removing <6> from <1678> leaving <178>
R7C3 - removing <26> from <12678> leaving <178>
R7C6 - removing <23> from <123> leaving <1>
R2C6 can only be <7>
R3C6 can only be <3>
R3C9 can only be <6>
R9C6 can only be <2>
R1C4 can only be <6>
R2C7 can only be <2>
R1C5 can only be <1>
R7C4 can only be <3>
R2C1 can only be <6>
R2C8 can only be <1>
R5C7 can only be <8>
R3C8 can only be <5>
R1C8 can only be <3>
R5C2 can only be <2>
R4C8 can only be <6>
R1C7 can only be <7>
R4C3 can only be <8>
R7C8 can only be <2>
R9C8 can only be <8>
R6C7 can only be <3>
R6C2 can only be <6>
R8C2 can only be <1>
R6C9 can only be <2>
R8C9 can only be <3>
R7C1 can only be <5>
R3C2 can only be <7>
R1C2 can only be <5>
R1C3 can only be <2>
R3C3 can only be <1>
R7C2 can only be <8>
R7C3 can only be <7>
R7C7 can only be <6>
R8C1 can only be <2>
R9C1 can only be <3>
R9C7 can only be <5>
R8C3 can only be <6>
R8C5 can only be <5>
R9C5 can only be <6>
Today's Sudoku Puzzles
All daily items change at midnight GMT – set your local time zone.
Note: BrainBashers has a Dark Mode setting.