The New Sudoku Players' Forum

[gklittle]

*-----------*
|9.8|...|.35|
|453|.1.|2.8|
|2.6|835|..9|
|---+---+---|
|..5|.9.|.82|
|..9|5.2|..7|
|762|...|95.|
|---+---+---|
|524|176|893|
|..1|.5.|726|
|697|...|5..|
*-----------*


*-----------------------------------------------------------*
| 9 17 8 | 2467 246 47 | 16 3 5 |
| 4 5 3 | 679 1 79 | 2 67 8 |
| 2 17 6 | 8 3 5 | 14 147 9 |
|-------------------+-------------------+-------------------|
| 13 34 5 | 467 9 147 | 1346 8 2 |
| 138 348 9 | 5 46 2 | 1346 146 7 |
| 7 6 2 | 34 48 1348 | 9 5 14 |
|-------------------+-------------------+-------------------|
| 5 2 4 | 1 7 6 | 8 9 3 |
| 38 38 1 | 49 5 49 | 7 2 6 |
| 6 9 7 | 23 28 38 | 5 14 14 |
*-----------------------------------------------------------*
After getting stuck on a puzzle, I turned it over to simple sudoku and asked for a hint. The cells R4 C6 and R4 C8 were highlighted. While trying to figure out this hint, I noticed the naked pair (38) and was able to go on and finish the puzzle. Can anyone tell me the logic technique behind highlighting those particular cells. The Solve step removed the 47 from R4 C6 and the 4 from R4 C8. Thank you,

[Guru]

Maybe i'm wrong, but according to http://act365.com/sudoku/ the puzzle is unsolvable

[simes]

Maybe i'm wrong, but according to http://act365.com/sudoku/ the puzzle is unsolvable

Yes, you are wrong! The puzzle has one solution. Did you copy it correctly?

gklittle, do you have the correct coordinates? r4c8 isn't even empty!

S

[gklittle]

"gklittle, do you have the correct coordinates? r4c8 isn't even empty! "

So sorry- it is R4C6 and R6C6

[Nick67]

Hi gklittle,

I re-created your situation. The hint indicated
a naked triple in column 6 (cells r1c6, r2c6, and r8c6).

Hope that helps,
Nick

[Sue De Coq]

Guru - That solver worked for me - I think you must have typo'd.

[Shazbot]

Can anyone tell me the logic technique behind highlighting those particular cells.

Here's what's in column 6

47
79
5
147
2
1348
6
49
38

The rows in bold show where the naked triple (4, 7, 9) can be found. This allows you to eliminate those numbers from other cells in column 6. The rows in italics - the ones the program highlighted for you - are the cells you can now eliminate candidates from, leaving you with 1 in row 4 and 138 in row 6.

It took me a while to figure this out too - the cells highlighted in yellow in Simple Sudoku are NOT where the pattern (naked triple, or whatever) is found - they're the cells you can change BECAUSE of the pattern. If you take a closer look, you'll actually see another set of cells highlighted in a different, less obvious colour, which shows you where the pattern was found.

But you're right - there's also a hidden pair (3,8) in that same column.

[gklittle]

Thanks to Nick and Shazbot for pointing out the naked triple.

To Shazbot,

"If you take a closer look, you'll actually see another set of cells highlighted in a different, less obvious colour, which shows you where the pattern was found"

The other cells weren't highlighted. Maybe there is a setting I missed.


I am really struggling with the naked triples. I have read the definition several times and still get confused when one of the numbers appear in another cell. For example, in the column mentioned, if one of the cells had been a 479, I would have chosen it and the 47 and 79 as a naked triple (would that have been correct?) However the fact that the 4 and 7 appear in other rows throws me off ----- I question why the 4 can't be in row 4 or 6, and why the 7 can't be in row 4?? Any help in my mastering this technique would be greatly appreciated!!!!!!!!!!!
47
79
5
147
2
1348
6
49
8

Off topic question - If a row consists of the following:
5 179 4 8 379 19 12 23 6 Would the 79s be a pair even though there is a 9 in another cell??

[Lardarse]

You should get the latest version, which would hilight in blue (and other colours) the cells that help you to remove candidates

[gklittle]

Thanks Lardarse, I have it now.

[emm]

if one of the cells had been a 479, I would have chosen it and the 47 and 79 as a naked triple (would that have been correct?)

Yes. Naked triples are three cells with a combination of the same three numbers and only those three numbers eg 47 49 79, 479 49 479, 49 79 479.

the fact that the 4 and 7 appear in other rows throws me off

The point is that you want those candidates to be in the other rows. Naked triples is about eliminating candidates from the other cells – not about placing the naked triple. All the naked triple tells you is that 4,7 & 9 must go in these three cells in some order but more importantly it tells that you can eliminate 4,7 & 9 from any other cells ie in row 4 and row 6.

If there aren’t any other 4,7 or 9s in the other cells then the naked triple doesn’t help at all.

5 179 4 8 379 19 12 23 6 ... Would the 79s be a pair even though there is a 9 in another cell??

No, this is not a pair. 5 179 4 8 379 1 12 23 6 = a hidden pair and 5 79 4 8 79 19 12 23 6 = a naked pair

Naked = the candidates are the only candidates in these cells therefore remove them from all other cells.
Hidden = the candidates are only in these cells therefore remove all other candidates from these cells.

[gklittle]

"Off topic question - If a row consists of the following:
5 179 4 8 379 19 12 23 6 Would the 79s be a pair even though there is a 9 in another cell??"

forget this question - "Senior Moment"

[gklittle]

Thanks Em,
I have been getting confused with looking at candidates vs looking at cells.
I think I am getting there. I just solved a puzzle with an x-wing and two naked triples ( or maybe a naked and a hidden)!!

[Brendan]

"Off topic question - If a row consists of the following:
5 179 4 8 379 19 12 23 6 Would the 79s be a pair even though there is a 9 in another cell??"

forget this question - "Senior Moment"

No, 5 1 4 8 7 9 2 3 6 is a possible solution to this row.

Brendan

[MCC]

No, 5 1 4 8 7 9 2 3 6 is a possible solution to this row.

Brendan

So are four other possible solutions. It doesn't help.