## Another Sudoku I couldnÂ´t solve

Post the puzzle or solving technique that's causing you trouble and someone will help

### Another Sudoku I couldnÂ´t solve

Hi, all,

I tried to solve the Sudoku # 647900 (very hard):

Code: Select all
`+-----+-----+-----+|. . .|. 1 .|. . 9||. . 7|. 5 .|2 . .||. 8 .|9 . 7|. . .|+-----+-----+-----+|. . 8|7 . .|. 2 6||3 . .|1 . 2|. . 8||6 2 .|. . 3|7 . .|+-----+-----+-----+|. . .|3 . 5|. 4 .||. . 6|. 2 .|9 . .||7 . .|. 4 .|. . .|+-----+-----+-----+`

I hardly found ANY hidden singles, this is what I could find out:

Code: Select all
`+-----------+------+-------------+|45 346 35..|2 1 68|458 7... 9...||9. 136 7...|4 5 68|2.. 138. 13..||2. 8.. 15..|9 3 7.|145 6... 145.|+-----------+------+-------------+|1. 5.. 8...|7 9 4.|3.. 2... 6...||3. 7.. 49..|1 6 2.|45. 59.. 8...||6. 2.. 49..|5 8 3.|7.. 19.. 14..|+-----------+------+-------------+|8. 9.. 12..|3 7 5.|6.. 4... 12..||45 34. 6...|8 2 1.|9.. 35.. 7...||7. 13. 1235|6 4 9.|158 1358 1235|+-----------+------+-------------+`

The biggest problems for me are:

1. the right start
2. to find TOO LESS (!!!) hidden singles
3. to pencilmark TOO MANY (!!!) cells
4. to find LESS than NO logic

I am sure, that I am the ONLY one in the WHOLE WORLD with LESS than NO brain! Otherwise I canÂ´t explain why I canÂ´t solve such EXTREMELY EASY Sudokus ((((

Any hints and tipps are appreciated. Thanks in advance
NoClue

Posts: 48
Joined: 01 April 2011

NoClue wrote:I tried to solve the Sudoku # 647900 (very hard):

Code: Select all
` . . . | . 1 . | . . 9  . . 7 | . 5 . | 2 . .  . 8 . | 9 . 7 | . . . -------+-------+------ . . 8 | 7 . . | . 2 6  3 . . | 1 . 2 | . . 8  6 2 . | . . 3 | 7 . . -------+-------+------ . . . | 3 . 5 | . 4 .  . . 6 | . 2 . | 9 . .  7 . . | . 4 . | . . . `

I hardly found ANY hidden singles

this is what I could find out:
Code: Select all
` *-----------------------------------------------------------* | 45    346   35    | 2     1     68    | 458   7     9     | | 9     136   7     | 4     5     68    | 2     138   13    | | 2     8     15    | 9     3     7     | 145   6     145   | |-------------------+-------------------+-------------------| | 1     5     8     | 7     9     4     | 3     2     6     | | 3     7     49    | 1     6     2     | 45    59    8     | | 6     2     49    | 5     8     3     | 7     19    14    | |-------------------+-------------------+-------------------| | 8     9     12    | 3     7     5     | 6     4     12    | | 45    34    6     | 8     2     1     | 9     35    7     | | 7     13    1235  | 6     4     9     | 158   1358  1235  | *-----------------------------------------------------------*`

28 cells given + 25 "hidden singles" = 53
(and you did get that far).
but this puzzle does need a tougher move --
finned X-wing excludes 1 at r9c2
the 1 for columns 3,7
is only in rows 3,9
except (a "fin") r7c3

Pat

Posts: 3692
Joined: 18 July 2005

### Re: Another Sudoku I couldnÂ´t solve

Hi, Pat,

many thanks for the tip with the "Finned X-Wing". I have extreme problems to spot strategies like this one. Even though I am dealing with Sudoku for more than 4 years.ItÂ´s like I have LESS than NO brain - LESS than NO memory - I hope to get endless frustrated, until IÂ´ll get MUCH better in playing Sudoku
NoClue

Posts: 48
Joined: 01 April 2011