chicago suntimes -- medium

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chicago suntimes -- medium

Postby silveraider2 » Sun Apr 06, 2008 10:52 pm



    whats my next move and why

chicago suntimes
medium

xx895x42x
xxx81xx5x
x5624xx8x
6x51x4x3x
xxx6x5xxx
x1x3x9xx5
3915682xx
x8x4315xx
564792318

somebody said to check 9 in box 4 but i see 2 possiblities
i always thought you never guess when playing
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Re: whats my next move and why

Postby Cec » Sun Apr 06, 2008 11:54 pm

silveraider2 wrote:"...somebody said to check 9 in box 4 but i see 2 possiblities
i always thought you never guess when playing"


Hi silveraider2,

Here is your pencilmark grid....
Code: Select all
 *--------------------------------------------------------------------*
 | 17     37     8      | 9      5      367    | 4      2      1367   |
 | 2479   2347   2379   | 8      1      367    | 679    5      3679   |
 | 179    5      6      | 2      4      37     | 179    8      1379   |
 |----------------------+----------------------+----------------------|
 | 6      27     5      | 1      278    4      | 789    3      279    |
 | 24789  2347   2379   | 6      278    5      | 1789   479    12479  |
 | 2478   1      27     | 3      278    9      | 678    467    5      |
 |----------------------+----------------------+----------------------|
 | 3      9      1      | 5      6      8      | 2      47     47     |
 | 27     8      27     | 4      3      1      | 5      679    679    |
 | 5      6      4      | 7      9      2      | 3      1      8      |
 *--------------------------------------------------------------------*

Within box4 (the middle left 3X3 box) the two candidate 9's only appear in row5 (r5). This "locks" the 9's within this box and therefore any other 9's in this row and outside this box can be excluded. You can now exclude the three 9's from r5 columns 7,8 and 9. This now leaves a "naked pair" [47] in c8 enabling all other 4's and 7's in c8 to be excluded which now solves cell r6c8.

Click on the following links which provide many basic solving techniques:

http://www.angusj.com/sudoku/hints.php
http://www.sadmansoftware.com/sudoku/techniques.htm
http://www.scanraid.com/BasicStrategies.htm

Cec
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Joined: 16 June 2005

Re: whats my next move and why

Postby hobiwan » Mon Apr 07, 2008 8:43 am

silveraider2, you already posted this puzzle in "Help with particular puzzles". Please direct all further requests to that thread.

silveraider2 wrote:chicago suntimes
medium

xx895x42x
xxx81xx5x
x5624xx8x
6x51x4x3x
xxx6x5xxx
x1x3x9xx5
3915682xx
x8x4315xx
564792318

somebody said to check 9 in box 4 but i see 2 possiblities
i always thought you never guess when playing

Somebody also gave you a link to a website, that describes the necessary technique in detail. Have you read that already?

On a sidenote: Two other people gave you links to descriptions, how you could post your puzzles in a user friendly way. It seems you have not read any of those links either...
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Location: Klagenfurt

Postby Pat » Tue Apr 08, 2008 11:51 am

silveraider2 wrote:
      Chicago Suntimes

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



somebody said to check 9 in box 4 but i see 2 possiblities

i always thought you never guess when playing



hi silveraider2

indeed in the earlier Topic, hobiwan advised you ---- and if that wasn't clear, you should've followed the link to the SuDoPedia -- also, i do notice that Cec has already added a detailed explanation, which however involves "pencilmarks" -- personally i'd like to do this without "pencilmarks" so here goes --
    look in box 4 --
    the 9 for this box
    must be in row 5

    so, exclude 9 in row 5 outside of this box !

    now in column 8, there's only one place for the 9
    ( not in row 5 )

to everyone else:
    the original post was indeed in another Topic, where silveraider2 was advised that a question concerning a published puzzle should go in the Pappocom section ( or in the non-Pappocom section, as appropriate ) -- this advice follows the rules set forth in the sticky -- please don't blame silveraider2 for following the sticky and re-posting here ( though it should've gone in the Pappocom section )
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Postby ronk » Tue Apr 08, 2008 12:53 pm

Pat wrote:... a published puzzle should go in the Pappocom section ( or in the non-Pappocom section, as appropriate ) -- this advice follows the rules set forth in the sticky -- please don't blame silveraider2 for following the sticky and re-posting here ( though it should've gone in the Pappocom section )[/list]

Thiings change. Pappocom is no longer associated with this site, so I see no reason anyone should care about making such distinctions.
    Moderator has now moved this to the Pappocom section
ronk
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