## how to solve ..

Post the puzzle or solving technique that's causing you trouble and someone will help

### how to solve ..

Hey guys,

how to solve this?

Mention the technique to solve this please

Drjay

Posts: 10
Joined: 30 July 2015

### Re: how to solve ..

I would use a Sashimi X-Wing, though there are doubtless other approaches that would also work.

..4....2.8.1..2.465324...89..8.49.32329..86.44..2..9.8.8.5..49..4............4.61
Last edited by JasonLion on Tue Aug 18, 2015 9:58 pm, edited 1 time in total.

JasonLion
2017 Supporter

Posts: 640
Joined: 25 October 2007
Location: Silver Spring, MD, USA

### Re: how to solve ..

What other techniques could I use? Thanks anyways.
Drjay

Posts: 10
Joined: 30 July 2015

### Re: how to solve ..

The simplest technique to use is a Skyscraper, which I'll illustrate here.

Code: Select all
`*--------------------------------------------------------------------------------*| 679     679     4        | 13789   135789  1357     | 1357    2       57       || 8       79      1        | 379    b3579    2        |a357     4       6        || 5       3       2        | 4       167     167      | 17      8       9        ||--------------------------+--------------------------+--------------------------|| 67      1567    8        | 167     4       9        |*7-5     3       2        || 3       2       9        | 17     c157     8        | 6      d157     4        || 4       1567    567      | 2       13567   13567    | 9       157     8        ||--------------------------+--------------------------+--------------------------|| 1267    8       367      | 5       12367   1367     | 4       9       37       || 12679   4       367      | 136789  1236789 1367     | 28      57      357      || 279     579     357      | 3789    23789   4        | 28      6       1        |*--------------------------------------------------------------------------------*`

Look at the cells I've marked abcd. Notice that there are only two 5's in Rows 2 and 5. If cell a was not 5 cell b would have to be 5 (only 2 5's in Row 3), so cell c would not be 5, so cell d would be 5 (2 5's in Row 5).

Reversing this argument, and assuming cell d was not 5 and following the path bcda you would have to conclude that cell a would be 5.

The result of all this is that at least one of cells a and d must be 5. They could both be 5 but they can't both be not 5.

Now look at cell r4c7, which I've marked with a *. Since it can see both cells a and d it can't be 5. You can remove the 5 from that cell, so it's 7 and the puzzle solves easily from there.

Here's a link to a good teaching site that discusses Skyscrapers and a lot of other solving techniques.

http://hodoku.sourceforge.net/en/techniques.php

PS: Jason's Sashimi Finned XWing and the Skyscraper use the same cells, but the XWing reasoning is a bit more involved. Sashimi Finned XWings are also discussed on the Hodoku site.

PPS: I can't see how you removed the 9 from r8c5. Maybe it's a limitation of your graphic, which looks like it can only accommodate 6 candidates in a cell.

Leren
Last edited by Leren on Tue Aug 18, 2015 9:26 pm, edited 3 times in total.
Leren

Posts: 3319
Joined: 03 June 2012

### Re: how to solve ..

Hi Jason, there appears to be a typo in your line format version of this puzzle. I can see a 1 missing from the end.

Leren
Leren

Posts: 3319
Joined: 03 June 2012

### Re: how to solve ..

Leren wrote:Hi Jason, there appears to be a typo in your line format version of this puzzle. I can see a 1 missing from the end.

Thanks for catching that. Fixed now.

JasonLion
2017 Supporter

Posts: 640
Joined: 25 October 2007
Location: Silver Spring, MD, USA