so few squares left but still stuck :'o(

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so few squares left but still stuck :'o(

Postby helpmeeee » Thu Mar 09, 2006 7:40 pm

9-- 6-- -58
8-4 --- 61-
62- -8- -3-

2-- 7-3 5-4
7-6 -5- 1-3
3-- 1-8 ---

478 316 925
562 8-- 371
193 527 846

thanks for your help
helpmeeee
 
Posts: 11
Joined: 12 July 2005

Postby tso » Thu Mar 09, 2006 8:48 pm

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


Look at the three cells marked with asterisks. The only candidates that can fit are 4, 7 and 9 in some order. Combine that with the 7 at r5c1 and the 7 in r7c2 -- only one cell remains in box 1 that can hold a 7.

For some, it's easier to see it the other way around -- there's a 1 and a 5 already placed in columns 4, 7 and 9. That leaves only two cells in row 3 that can hold a 1 or a 5. Since r3c3 and r3c6 must hold a 1 and a 5 in some order, they *can't* hold a 7 -- and again, only one cell remains in box 1 that can hold a 7.
tso
 
Posts: 798
Joined: 22 June 2005


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