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Guest Guest

Posted: Tue Feb 07, 2006 11:39 am Post subject: 7 Feb 2006 


Hi every one,
I am a relative new comer to suduko. I am stuck on todays puzzle. This is how far I've got:
Code:  9476
3895
9728
51734
3642175
4951
381
76249
1935 
Can anyone give me a few hints on how to get to the next step, please?
Many Thanks
Jude 

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Steve R
Joined: 24 Oct 2005 Posts: 289 Location: Birmingham, England

Posted: Tue Feb 07, 2006 12:08 pm Post subject: 7 Feb 2006 


Jude:
There is a pair in the third row.
Check where 5 and 6 may be placed. Only two cells admit these values. Now, keeping in mind that these two cells are to be filled by a 5 or a 6, there is only one place for a 3 in the top lefthand box.
I hope this trick gets you past the hurdle. Good luck!
Steve 

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igolf4birdies
Joined: 01 Feb 2006 Posts: 4 Location: Russell Springs, KY

Posted: Thu Feb 09, 2006 4:29 pm Post subject: 2/7/06 Puzzle 


I'm stuck. I need some logic for my next step. I had already found the 5,6 pair in the third row as well as the 2,7 pair in the sixth row. But now I'm stuck.
3 8 _ _ 9 4 _ 7 6
_ _ _ _ 3 8 _ 9 5
_ _ 9 _ 7 2 8 _ _
_ 5 1 7 _ 3 _ 2 4
_ 3 6 4 2 1 7 5 _
4 _ _ 9 _ 5 _ 1 _
_ _ 3 8 1 _ _ _ _
7 6 _ 2 4 9 _ _ _
1 9 _ 3 5 _ _ _ _
Thanks in advance.
Rick 

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Steve R
Joined: 24 Oct 2005 Posts: 289 Location: Birmingham, England

Posted: Fri Feb 10, 2006 1:33 am Post subject: 2/7/06 Puzzle 


If it’s any consolation, this ranks in my mind at about as tough as puzzles on this site get.
You will see that the 2 in the top righthand box must occupy column7. Equally the 6 in the middle righthand box occupies column 7.
Taking account of all these facts, what is left for r9c7?
Steve 

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Guest Guest

Posted: Sun Feb 12, 2006 2:40 pm Post subject: 


Thanks Steve, I managed to get out, but need to practice that trick a bit more.
Jude 

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jeeperndbb Guest

Posted: Mon Feb 13, 2006 10:11 pm Post subject: The two 


How did we get the 2 in r4c8? 

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David Bryant
Joined: 29 Jul 2005 Posts: 559 Location: Denver, Colorado

Posted: Mon Feb 13, 2006 11:03 pm Post subject: Re: The two 


jeeperndbb wrote:  How did we get the 2 in r4c8? 
The short answer is it can't fit anywhere else in row 4. Let's look at the grid.
Code:  3 8 _ _ 9 4 _ 7 6
_ _ _ _ 3 8 _ 9 5
_ _ 9 _ 7 2 8 _ _
_ 5 1 7 _ 3 _ _ 4
_ 3 6 4 2 1 7 5 _
4 _ _ 9 _ 5 _ 1 _
_ _ 3 8 1 _ _ _ _
7 6 _ 2 4 9 _ _ _
1 9 _ 3 5 _ _ _ _ 
 We can't put either an "8" or a "9" at r2c1. r3c1. or r7c1. So the "hidden pair" {8, 9} must lie in r4c1 & r5c1. In other words, we can't put a "2" at r4c1.
 We can't put a "2" at r4c5 because of the "2" at r5c5.
 The "2" in the top right 3x3 box must lie in r1c7 or r2c7 because of the "2" at r3c6. So we can't put a "2" at r4c7.
 r4c8 is the only spot left for a "2" in row 4. dcb 

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