dailysudoku.com

[Deano]

i have achieved the following for the august 27th puzzle:

623 -18 97-
817 9-2 6-3
-*- 763 821

78- 23- 1--
2-1 --- 3-7
-36 179 -82

372 691 --8
165 --7 239
948 325 716

the "Hint" given is for a "5" in the cell where i place the asterisk. can someone explain to me why this has to be a 5? i see the 5 being in either r3c1 or r3c2 and not just 23c2. i also have a 5 as a possibility in r6c1 or r5c2. help!

[David Bryant]

You need to analyze the "naked pairs" in this puzzle, Deano.

You can see already that r5c6 and r6c6 must contain the values {4, 6} in some order -- those are the only values missing in column 6. This means that the values {5, 8} must lie in the two cells r5c4 and r5c5, in some order.

Therefore the three remaining open cells in row 5 (that is, r5c2, r5c6, and r5c8) can only contain the values {4, 6, 9}. Now look at the second column -- since "4" and "6" are already entered there, r5c2 must be a "9".

This forces the "5" in r3c2, where you placed the *. dcb

[geoff h]

David,

I think you meant to say the pair of 4,6 are contained in r4c6 and r5c6 - r6c6 already contains the Nr 9!! This then leads to a pair of 5,8 in r5c4 and r5c5 as you said, which leads to placing the Nr 9 in r5c2.

The puzzle should be easily solved from there.

Cheers.

[Guest]

You're right, Geoff -- my bad. Thanks for the clarification. dcb