Everything about Sudoku that doesn't fit in one of the other sections

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`+---+---+---+|819|263|547||756|48.|3..||243|57.|...|+---+---+---+|3.1|...|...||.24|1.7|.8.||...|...|..1|+---+---+---+|...|..4|15.||4.5|.1.|..6||1.2|.56|794|+---+---+---+`
LBJOHN

Posts: 3
Joined: 15 December 2005

Hi LBJ - naked pairs in column 6 and then row 8 are the key to unlocking this puzzle.

Naked pair = If the same two numbers are the only two numbers in two cells in a row, column or box then you can remove them from all other cells in that row, column or box.

Hint - which two numbers can only go in the last two cells in box 2?
emm

Posts: 987
Joined: 02 July 2005

Call me stupid. But which is the next number that you can write in. Please simply reply with a number and the reason.
LBJOHN

Posts: 3
Joined: 15 December 2005

Your beginning candidates for r8c6 are 2, 8 and 9. The only places for 1 and 9 to go in box 2 are in column 6, so the 9 can be eliminated from r8c6, leaving 2 and 8. 2 and 8 are also the only candidates for r8c7, so you can remove them from all other cells in row 8. This leaves 3 as the only candidate for r8c8.
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` *-----------* |819|263|547| |756|48.|3..| |243|57.|...| |---+---+---| |3.1|...|...| |.24|1.7|.8.| |...|...|..1| |---+---+---| |...|..4|15.| |4.5|.1.|.36| |1.2|.56|794| *-----------*  *--------------------------------------------------------------------* | 8      1      9      | 2      6      3      | 5      4      7      | | 7      5      6      | 4      8      19     | 3      12     29     | | 2      4      3      | 5      7      19     | 689    16     89     | |----------------------+----------------------+----------------------| | 3      6789   1      | 689    249    258    | 2469   267    259    | | 569    2      4      | 1      39     7      | 69     8      359    | | 569    6789   78     | 3689   2349   258    | 2469   267    1      | |----------------------+----------------------+----------------------| | 69     36789  78     | 3789   239    4      | 1      5      28     | | 4      79     5      | 79     1      28     | 28     3      6      | | 1      38     2      | 38     5      6      | 7      9      4      | *--------------------------------------------------------------------*`

After this, your next step is to see where a 3 can go in column 9.
Shazbot

Posts: 220
Joined: 24 September 2005