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Complex innies/outies – part two

I saw two comments (by Graham and David) for the puzzle posted on October 25, and I think there’s a little clarification on “complext innies/outies” that should be made here. You should look for innies/outies in more than just one row/column/nonet. This is a good example of such puzzle. See this image:
(click to download or right-click to save the image!)

Fiendish Killer Sudoku Book

To see the solution to this puzzle click here
The cell outlined in red is the only cell sticking out of all cages that belong to the first 5 columns. So it’s value must be: (Sum of All Cages in First 5 Columns) – 5*45. In this case it equates to: (4+9+15+28+10+17+21+12+14+7+24+11+12+21+14+13)-5*45 = 232 – 225 = 7. Of course you could’ve done it the other way – as an innie of the last 4 columns. And remember – whenever you find an innie/outie in a symetrical puzzle, there’s always one more – exactly opposite to the one you just found. I hope you see which one I’m talking about. It’s a coincidence that in this puzzle the value of the opposite innie/outie is identical (it’s also 7). Once you solve those two and solve the two cells in the upper left corner, there’s nothing fancy about yesterday’s puzzle :).
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  1. Agueda
    Posted November 2, 2005 at 1:39 pm | Permalink

    Please, I need an answer ¿Is it possible to have the same number inside a box which is between two nonets? For example, the 16 between the two upper right nonets. Should it be a 7, 7 & 2?

  2. Posted November 2, 2005 at 2:18 pm | Permalink

    Agueda, there has been some discussion regarding this on this and other sites too.

    Basically, my puzzles CAN NOT have two occurrences of the same number inside one “cage”, even if that is allowed by other Sudoku rules.

One Trackback

  • By The Law of Leftovers (LOL) on September 12, 2011 at 2:16 am

    […] technique is somewhat similar to innies/outies which is used for solving Killer Sudoku puzzles, but there is no math involved and, again, it […]

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