## Very hard with Xwings...

Advanced methods and approaches for solving Sudoku puzzles

### Very hard with Xwings...

Any suggestions how to proceed with this?

6*9 823 4*7
*7* 69* *8*
8*3 *** 6**

*** 382 ***
*4* 956 *3*
3** 417 ***

*62 **8 1**
*8* 2*9 *6*
937 *6* 8*2

I can see 2 xwings of 2's and several pairs (mainly rows 5 and 6) but to no real avail
Arnie

Posts: 49
Joined: 19 May 2005

Take a really good look at box 6.

When you are finished with looking at it then you should be a able to fill in the number 7 in column 8.
Animator

Posts: 469
Joined: 08 April 2005

Possibilities for box 6...

579 1457 1456
27 3 18
59 25 86

cells r5c7 r5c9 form pairs with other cells in row 5....as does 86 in row 6...
I sense from your post you can exclude 7 from r4c8 but I cannot see how...
Arnie

Posts: 49
Joined: 19 May 2005

There are two group of numbers, both containing 4 numbers...

First one: 2, 5, 7, 9
Second one: 1, 4, 6, 8

I'm sure you would know what to do if you had these candidates:

2579 145678 14568
2579 3 1468
2579 2579 1468
Animator

Posts: 469
Joined: 08 April 2005

...hence 7 cannot be in r4c8 ! ...so 7 must be in r6c8...

I was looking for pairs or triplets in box 6 --never thought to look for 2 sets of 4 numbers....thanks
Arnie

Posts: 49
Joined: 19 May 2005

Do you have the original grid?

Looking at the above posts I'm looking at the 7 in Row 7, not R6C8. But maybe I've read something wrong.
little Zivvy

Posts: 7
Joined: 13 June 2005

The original grid was a "very hard" from the Sudoku programme :

6*9 *2* 4*7
*7* *** *8*
**3 *** 6**

*** 382 ***
*4* 9*6 *3*
*** 417 ***

**2 *** 1**
*8* *** *6*
9*7 *6* 8*2
Arnie

Posts: 49
Joined: 19 May 2005