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		| pbreinhart 
 
 
 Joined: 21 Sep 2007
 Posts: 9
 Location: Atlanta, GA
 
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				|  Posted: Tue Feb 09, 2016 10:32 pm    Post subject: An old puzzle march 26, 08 |   |  
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				| I haven't a clue as to why a "7" is suggested for R5C7 when I click the hint button.  I would very much appreciate any info.  Thanks. Here is the puzzle:
 
  	  | Code: |  	  | +-----------+------------+---------+
 | 1 245 458 | 6   89  29 | 45 3  7 |
 | 6 57  58  | 137 378 4  | 2  15 9 |
 | 9 247 3   | 17  5   27 | 46 16 8 |
 +-----------+------------+---------+
 | 2 6   59  | 59  1   8  | 7  4  3 |
 | 4 59  1   | 579 7   3  | 8  2  6 |
 | 8 3   7   | 2   4   6  | 1  9  5 |
 +-----------+------------+---------+
 | 5 49  6   | 479 2   79 | 3  8  1 |
 | 3 1   2   | 8   6   5  | 9  7  4 |
 | 7 8   49  | 349 39  1  | 56 56 2 |
 +-----------+------------+---------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 The numbers in that cell are 79 before the hint.
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		| yeoks 
 
 
 Joined: 16 May 2010
 Posts: 33
 
 
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				|  Posted: Wed Feb 10, 2016 11:29 am    Post subject: |   |  
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				|  	  | Code: |  	  | +-----------+------------+---------+
 | 1 245 458 | 6   89  29 | 45 3  7 |
 | 6 57  58  | 137 378 4  | 2  15 9 |
 | 9 247 3   | 17  5   27 | 46 16 8 |
 +-----------+------------+---------+
 | 2 6   59  | 59  1   8  | 7  4  3 |
 | 4 59  1   | 579 79  3  | 8  2  6 |
 | 8 3   7   | 2   4   6  | 1  9  5 |
 +-----------+------------+---------+
 | 5 49  6   | 479 2   79 | 3  8  1 |
 | 3 1   2   | 8   6   5  | 9  7  4 |
 | 7 8   49  | 349 39  1  | 56 56 2 |
 +-----------+------------+---------+
 
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 Play this puzzle online at the Daily Sudoku site
 
 XY-Wing 59-7 pivoted in r5c2 removes (7) from r2c5, leaving r5c5 as the only cell with a (7) in column 5.
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		| pbreinhart 
 
 
 Joined: 21 Sep 2007
 Posts: 9
 Location: Atlanta, GA
 
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				|  Posted: Wed Feb 10, 2016 8:36 pm    Post subject: |   |  
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				| Thanks.  Very clear. Then the puzzle goes on to say that that R7C6 should be a 7.  I am not sure how this is arrived at.
 
  	  | Code: |  	  | +-----------+-----------+---------+
 | 1 245 458 | 6   89 29 | 45 3  7 |
 | 6 57  58  | 137 38 4  | 2  15 9 |
 | 9 247 3   | 17  5  27 | 46 16 8 |
 +-----------+-----------+---------+
 | 2 6   59  | 59  1  8  | 7  4  3 |
 | 4 59  1   | 59  7  3  | 8  2  6 |
 | 8 3   7   | 2   4  6  | 1  9  5 |
 +-----------+-----------+---------+
 | 5 49  6   | 47  2  7  | 3  8  1 |
 | 3 1   2   | 8   6  5  | 9  7  4 |
 | 7 8   49  | 34  39 1  | 56 56 2 |
 +-----------+-----------+---------+
 
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 Play this puzzle online at the Daily Sudoku site
 The square R7C6 is originally 79 and I don't know how to get rid of the 9 or the other 7 in the box.  Thanks.
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		| dongrave 
 
 
 Joined: 06 Mar 2014
 Posts: 572
 
 
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				|  Posted: Thu Feb 11, 2016 4:48 am    Post subject: |   |  
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				| Wow!  That took me too long to find!  I used the 458 XYZ Wing with pivot at r1c3 which removed the 5 from r1c2 which then opened up the 24-9 XY Wing with pivot at r1c2 which removed the 9 from r7c6!  Good one! |  | 
	
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		| hughwill 
 
 
 Joined: 05 Apr 2010
 Posts: 424
 Location: Birmingham UK
 
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				|  Posted: Thu Feb 11, 2016 9:46 am    Post subject: |   |  
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				|  	  | dongrave wrote: |  	  | Wow!  That took me too long to find!  I used the 458 XYZ Wing with pivot at r1c3 which removed the 5 from r1c2 which then opened up the 24-9 XY Wing with pivot at r1c2 which removed the 9 from r7c6!  Good one! | 
 
 In fact the first 59-7 XY-Wing isn't required- Dongrave's two wings do it all.
 
 Hugh
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		| pbreinhart 
 
 
 Joined: 21 Sep 2007
 Posts: 9
 Location: Atlanta, GA
 
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				|  Posted: Thu Feb 11, 2016 10:40 pm    Post subject: |   |  
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				| Thank you both.  Very impressive resolution of the puzzle. |  | 
	
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