dailysudoku.com

[somghd1]

Sudoku 22Oct2005

5x8 xx3 4x1
xxx 458 x39
x3x 1x7 8x5

8xx 2xx 356
x62 3x5 987
35x x86 142

7x5 8xx x93
x1x 539 xx8
983 xx2 514

So far so good, but i got stuck.
The hint gives me r7c2=2
My bad day, don’t understand the hint.
Can someone explain the hint?
Thx.

[Steve R]

Maybe this will help.
From the bottom three boxes, the 4 in the bottom left hand box must be in the middle of the three rows.
Gong down column 2, the entry for row 7 column 2 is either a 2 or a 4.

Steve

[David Bryant]

First of all, count the possibilities remaining in row 7. Five values are already filled in. The only remaining values are {1, 2, 4, 6}.

The values {1, 6} are already filled in in column 2. So r7c2 can only be {2, 4}. But now look at the bottom center 3x3 box, and the "4" at r9c9. Clearly the "4" in row 7 must fit in the bottom center 3x3 box -- that is, in r7c5 or r7c6. So r7c2 can't be a "4", and it must be a "2". dcb