## Help with completion of hard puzzle

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

### Help with completion of hard puzzle

Hi All,

Have a puzzle that I have gotten so far and no more, and am looking for some advice about finishing it.

The starting puzzle is:
Code: Select all
`. . . | . . . | 3 . 8. . 6 | . . 4 | . 7 5. . 2 | . 9 . | . . .------+-------+------. 6 3 | 9 5 . | 7 . 2. 7 . | . . . | . 6 11 . 5 | . 2 6 | . 9 3------+-------+------. . . | . 3 . | 6 . .6 3 . | 4 . . | 2 . .9 . 7 | . . . | . . . `

After some manipulation you get:
Code: Select all
`457  9      14   | 156   167  57   | 3   2    8  3    18     6    | 2     18   4    | 9   7    54578 1458   2    | 1358  9    3578 | 14  14   6-----------------+-----------------+-------------48   6      3    | 9     5    1    | 7   48   22    7      9    | 38    4    38   | 5   6    11    48     5    | 7     2    6    | 48  9    3-----------------+-----------------+-------------458  12458  148  | 158   3    2578 | 6   158  796    3      18   | 4     178  5789 | 2   158  799    1258   7    | 1568  168  258  | 18  3    4`

I am now stuck with the next move(s). Where to now?

regards,
Rich
RichardS

Posts: 4
Joined: 23 January 2006

Hi RichardS.

You have a naked pair in row 3 in cells r3c7/r3c8. See if you can solve from here.

Regards, Carcul
Carcul

Posts: 724
Joined: 04 November 2005

### Re: Help with completion of hard puzzle

richards wrote:"..looking for some advice about finishing it.."

Hi Richard and welcome to the Forum,
To complement Carcul's help, in row 3 there is a "naked pair" [14] in box 3 (the puzzle grid contains nine 3X3 'boxes' and are identified as numbered 1 to 9). This means all other candidates 1 and 4 in this row can be excluded.

In column 3 notice that candidate 8 must go either in r7c3 or r8c3 - it doesn't matter at this stage which of these two cells the 8 must go. Because these candidate 8's are "locked" in column 3 of box7 then the remaining candidate 8's within box7 can be excluded. This is another of a number of basic solving techniques which are explained by clicking on HERE and HERE

Try spotting the "naked quad" in row 7 (the same four numbers or a combination thereof appearing in only four cells) which enables any of these same candidates to be excluded if existing in other cells of this row..The rest of the puzzle can be solved by identifying "hidden" or "naked" singles.

If you are still stuck then ask for further help.

Cec
Cec

Posts: 1039
Joined: 16 June 2005

Thanks for the help guys.

Will let you know if I need more help

Rich
RichardS

Posts: 4
Joined: 23 January 2006

### Re: Help with completion of hard puzzle

cecbevwr wrote:Try spotting the "naked quad" in row 7 (the same four numbers or a combination thereof appearing in only four cells)

Just for a check, is the naked quad you are refering to 1458?

regards,
Rich
RichardS

Posts: 4
Joined: 23 January 2006

Yes it is.

MCC
MCC

Posts: 1275
Joined: 08 June 2005

Great, thanks all

Solved it.

Rich
RichardS

Posts: 4
Joined: 23 January 2006

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