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PunditLisa
12-22-2006, 09:47 PM
Okay, I've been working on a Sodoku puzzle for hours and I'm completely stuck. Assuming my additions are correct, here's where I've gotten hopelessly stuck.

XX73X4XX2
X41692X73
239X7X416
X93XXX1XX
18XXXX3X5
X2XX3194X
XX2X8X731
978163254
31X2X7689

Can someone point me to the next step?

P.S. If my additions aren't correct, here is the original puzzle:

XX73X4XX2
X4XX9XXX3
2XXX7X4XX
X93XXXXXX
1XXXXXXX5
XXXXXX94X
XX2X8XXX1
9XXX6XX5X
3XX2X76XX

Happy solving!

Biffy the Elephant Shrew
12-22-2006, 10:39 PM
1 in the top row is obvious.

Look for the 6 in the left middle box. Not hard to narrow down. Third column, sixth row.

Now you know which column in the left middle box has a 5 in it, which tells you where 5 in the left top box is. That in turn gives you the 5 in the right middle box, and then the 8 in the same box, and then you can easily get all the 8s in the puzzle. Then everything else should start falling into place.

PunditLisa
12-22-2006, 10:55 PM
1 in the top row is obvious.

Look for the 6 in the left middle box. Not hard to narrow down. Third column, sixth row.

But the 6 could have also been put in the first column, 6th row...? Am I missing something?

Biffy the Elephant Shrew
12-22-2006, 11:03 PM
If the 6 were in the first column, there would be no possibility for the third column to have a 6 (since there is already a 6 in the ninth row). So 6 must be in the third column, fifth or sixth rows. And 6 in the sixth row is ruled out in the center box and the right middle box, so that leaves sixth row for the third column.

PunditLisa
12-22-2006, 11:25 PM
Ah, thank you, Biffy! I can finally go to sleep.

Snarky_Kong
12-22-2006, 11:42 PM
657314892
841692573
239875416
793456128
184927365
526138947
462581731
918763254
375241689

The solved sudoku for reference.