dailysudoku.com

[geoff h]

I am a new user to this site, but am an experienced sudoku player ( or so I thought !!)

Re today's puzzle. I got stuck and when I asked for a hint from this site, they gave me a 3 in row 3 column 3 of the middle square in the bottom row of the sudoku. I had my options as either a 2 or a 3 for this square, but can't see how the 2 was eliminated!!

Can anyone help??

[someone_somewhere]

Here is a trace to get to this point (the fists numbers in brackets, mean the position on a 9 by 9 board. The upper left cell is (1 1) the bottom right cell is (9 9):

Initial SuDoku Table

0 0 1 0 0 4 7 0 0
0 0 0 7 0 0 0 3 8
6 0 0 9 0 8 4 5 0
5 0 9 0 0 0 0 0 0
0 7 0 0 0 0 0 1 0
0 0 0 0 0 0 3 0 9
0 5 2 1 0 7 0 0 4
7 8 0 0 0 9 0 0 0
0 0 6 8 0 0 5 0 0

(1 1)->8 (3 3)->7 (5 5)->9 unique horizontal
(2 3)->5 (5 9)->5 unique vertical
(6 6)->5 unique vertical

Exclude Nr=1 from (9 9) becasue Nr has to be in (8 7) or (8 9)
Excluded Nr=3 from (4 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (9 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (5 4) because it is in (5 1) and (5 3)
Excluded Nr=3 from (5 6) because it is in (5 1) and (5 3)
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=3 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8

(4 6)->1 unique in 3x3
(4 4)->3 unique in 3x3
(9 6)->3 (8 9)->3 unique vertical

Hope I could help you!

[someone_somewhere]

Sorry, some small mistakes in some lines.
Here the corrected hint:

(1 1)->8 (3 3)->7 (5 5)->9 unique horizontal
(2 3)->5 (5 9)->5 unique vertical
(6 6)->5 unique vertical
Exclude Nr=1 from (9 9) becasue Nr has to be in (8 7) or (8 9)
Excluded Nr=3 from (4 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (9 2) because it is in (1 2) and (3 2)
Excluded Nr=3 from (5 4) because it is in (5 1) and (5 3)
Excluded Nr=3 from (5 6) because it is in (5 1) and (5 3)
Exclude Nr=1 from (4 5) because of numbers= 7 8
Exclude Nr=1 from (6 5) because of numbers= 7 8
Exclude Nr=2 from (4 5) because of numbers= 7 8
Exclude Nr=2 from (6 5) because of numbers= 7 8
Exclude Nr=3 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (4 5) because of numbers= 7 8
Exclude Nr=4 from (6 5) because of numbers= 7 8
Exclude Nr=6 from (4 5) because of numbers= 7 8
Exclude Nr=6 from (6 5) because of numbers= 7 8
LEVEL 5 - Exclude based on vertical Exact 2 same Numbers =9

(4 6)->1 unique in 3x3
(4 4)->3 unique in 3x3
(9 6)->3 (8 9)->3 unique vertical

[geoff h]

Okay, thanks very much for your reply.
However, still a bit confused!!

I agreed with all your logic movements, except for the following.

Exclude Nr 3 from ( 4 2 ) because it's in ( 1 2 ) and ( 3 2 )
Exclude Nr 3 from ( 9 2 ) because it's in ( 1 2 ) and ( 3 2 )
Exclude Nr 3 from ( 5 4 ) because it's in ( 5 1 ) and ( 5 3 )
Exclude Nr 3 from ( 5 6 ) because it's in ( 5 1 ) and ( 5 3 )

I can't follow the logic of eliminating the Number 3 as you have shown. Are there some hidden pairs or triples that I'm missing?? I have the Number 3 appearing at ( 1 2 ) ( 3 2 ) ( 4 2 ) and ( 9 2 ). So how are you eliminating it as shown?

Thanks

[someone_somewhere]

Hi,
the Nr 3 from position (2 cuases exludes of Nr 3 in (2 1) and (2 2). Remains Nr 3 to be in (1 2) or (3 2).

Is this what you were looking for?

[someone_somewhere]

I ment position (2 and not (2 )

[someone_somewhere]

Sorry, I try again:
position 2 and 8

It looks like the number 8 followed by the ) is giving us the sign

[Guest]

Yes, thanks for your reply. I already have Nr 3 excluded from ( 2 1 ) and
( 2 2 ). However, I have Nr 3 in ( 1 2 ), ( 3 2 ), ( 4 2 ) and ( 9 2 ) so I don't understand when you say you can exclude Nr 3 from ( 4 2 ) and ( 9 2 ) because it's in ( 1 2 ) and ( 3 2 ).

Sorry for all the questions, but it's really got me beat!!

[geoff h]

Sorry, I just had another look and see where I went wrong. Nr 3 has to be in either ( 1 2 ) or ( 3 2 ). Thanks again for your help - it's okay now.

Cheers.

[harps]

I'm in a quandry

[harps]

can you give me another push start after these clues above.

[geoff h]

The Number 3 can be excluded from ( 4 2 ) and ( 9 2 ) because it is already in ( 1 2 ) and ( 3 2 ). Nr 3 MUST be in either ( 1 2 ) or ( 3 2 ) because they are the only cells in the first square that support the Number 3. Therefore NR 3 can not appear anywhere else in Column 2.

Similar logic can be applied to the exclusion of Nr 3 from ( 5 4 ) and ( 5 6 ) because Nr 3 MUST be in either ( 5 1 ) or ( 5 3 ) and therefore can
not appear anywhere else in Row 5.

Hope this helps.

[Lena]

Thanks for the explanation. I needed the same hint. Now it makes sense!