- Code: Select all
`*-----------*`

|...|...|.3.|

|47.|...|...|

|9..|.1.|...|

|---+---+---|

|..8|1..|.2.|

|2..|5..|..7|

|..3|.6.|.1.|

|---+---+---|

|..5|.7.|..2|

|...|..5|..9|

|..7|2.8|..1|

*-----------*

This is actually a very easy puzzle. After marking off the clues and looking for naked and hidden singles, you end up here, which is close to what you have pencilled in on your diagram.

- Code: Select all
`*-------------------------------------------------------*`

|*568 *568 126 | 4789 2489-5 479 | 124678-5 3 468-5 |

| 4 7 12 | 3 258 6 | 1258 9 58 |

| 9 3 26 | 478 1 47 | 245678 45678 4568 |

|--------------+-----------------+----------------------|

| 567 456 8 | 1 49 479 | 4569 2 3 |

| 2 1 9 | 5 48 3 | 468 468 7 |

| 57 45 3 | 4789 6 2 | 4589 1 458 |

|--------------+-----------------+----------------------|

| 368 689 5 | 49 7 1 | 3468 468 2 |

| 1 2 4 | 6 3 5 | 78 78 9 |

| 36 69 7 | 2 49 8 | 3456 456 1 |

*-------------------------------------------------------*

There is a Box/Row intersection (pointing pair) of 5's in Box 1 in the cells marked *. As these are the only two 5's in Box 1, one of them must be True, so you can eliminate the other three 5's in Row 1, as I've indicated.

The puzzle then just solves with a cascade of singles, the first of which is that r2c5 must be 5 as it is the only 5 in Column 5 and Box 2.

If you really don't know about intersection removals, let me know and I'll give you some links to some excellent teaching sites.

Leren