dailysudoku.com

[daykart]

5 _ _ 1 _ _ _ 3 _
_ _ 3 _ 4 9 5 7 _
_ 9 _ _ _ _ 8 1 _

_ _ _ _ _ _ _ 6 _
_ 2 _ 5 _ 1 _ 8 _
_ 3 _ _ _ _ _ _ _

3 5 7 _ 1 _ _ 2 _
_ _ 6 4 7 _ 3 _ _
_ _ _ _ _ 3 7 _ 1

Here are all 9 rows. I have filled in the pencil marks, but have major difficulty deciding what goes where. Can you help???
I am including the rows and col that I would like some help with.

c 7 r1 (2469) r4 (12) r5 (49) r6 (12) r7 (649)
c 8 r6 ((49) r8 (59) r9 (459)
c 9 r1 (2469) r2 (26) r3(246) r4 (357) r5 (37) r6 (57) r7 (4689) r8 (89)

then
r2 c1 (128) c2 (16) c4 (268) c9 (26)
r5 c1 (67) c3 (49) c5 (36) c6 (49) c8 (37)
r8 c1 (1289) c2 (1 c6 (258) c8 (59) c9 (89)

I should be able to eliminate, but I just do not see it.

Grateful for any help.

Thanks

[Jimmy Chan]

First: Focus on Block 9
Second: 8 must be in r7c9 or r8c9, the reason is trivial
Third: 8 must not be in r7c9 because r7c7 and r7c9 must either be 4 or 6 (reason: in row 7, 4 must be in r7c7 and r7c9 ; in block 9, 6 must be in r7c7 and r7c9).
Fourth: Therefore 8 must be in r8c9.

[David Bryant]

To get your next number, look at the lower left 3x3 box. It's clear that the "4" in this box must fit in row 9. Therefore the "4" in column 8 must appear at r6c8, because it can't fit at r8c8 or r9c8.

Now you have the {5, 9} pair in r8c8 & r9c8, leaving "8" as the only possibility at r8c9, and the {4, 6} pair in r7c7 & r7c9.

Hopefully that's enough to get you rolling ... there's also an X-Wing in the "1"s at r2c1, r2c2, r8c1, & r8c2 that should help you uncover a hidden pair in the middle left 3x3 box. And there's another hidden pair, in row 5, but I don't want to spoil all the fun ...

Enjoy! dcb

[Guest]

There are several tools you need to use to solve this puzzle. First, look for naked pairs, starting within Box 6 and then then in row 5. That, I believe should lead you to place an 8 in r7c6. Second, you can eliminate some options by checking for isolated numbers within a box. For example, in box 9 I believe 6's can only go in the top row within the box. Therefore, 6's can be elimiated from the top row in boxes 7 and 8. Also, there was one hidden pair in the puzzle. I found the definitions at angusa.com/suduko/hints.php to be very helpful.

[daykart]

Dear Jimmy, David, and Guest,

Thanks for your clues. I just solved the puzzle, and could not believe that I was uncapable of the logic that you showed me.
It was toooo obvious, I blindman, not me, could see it.
The 46 pair in r7 of box 9 was so obvious (yuk), and David the 4 in r9 was simply shouting, but I did not hear it.

Again, thank you all so much, and Guest, I will look up the definition site you spoke of.

Have a wonderful Thanksgiving

Daykart