## Problem at first Hard

Advanced methods and approaches for solving Sudoku puzzles

### Problem at first Hard

In asking "Arnie" to explain the logic of where a number goes in row 8 of "HopDunne's unsolved puzzle (June 28), I can follow "Simes" logic that "There's only one cell (sic. column 7) in row 8 that can contain a 7". However, as 7 is also a candidate in four cells in row 7 (columns 2,4,7 and 8) and also a candidate in another three cells in row 9 (columns 2,4 and 7) I still don't understand why 7 must go in row 8 when it is also a candidate for other cells in rows 7 or 9 as mentioned above.
I don't know if "HopDunne", who instigated this puzzle, can follow the explanations given but I am still confused in advancing further with this puzzle even if it doesn't have a solution. I am greatful for the feedback from other members to this intriguing sudoku and wish to remove my frustration when I can't understand the explanations given.
Regards again, Bonsai Cec
Cec

Posts: 1039
Joined: 16 June 2005

Sorry to butt in again... but, I'm going to anyway:D

You're getting too deep, it's much simpler than that.

Every row (and column and box) has to contain each of the number 1 to 9.

There's only one cell in row 8 that contain a 7, so that cell must contain the 7.

There's no need to involve rows 7 and 9.
Last edited by simes on Sun Dec 11, 2011 2:32 pm, edited 1 time in total.
simes

Posts: 324
Joined: 11 March 2005
Location: UK

Please, stop doing that.

If you want to post a message about a thread/topic then use the reply button and not the 'new topic' button.

What you are doing now is splitting up the topic in two, and it is really hard for people to follow the topic and more important, it might result in the same question being asked multiple times. Since others can't find it.

I strongly suggest that this topic is closed and that this one is used: http://forum.enjoysudoku.com/viewtopic.php?t=715 .
Animator

Posts: 469
Joined: 08 April 2005

Return to Advanced solving techniques