## Globe and Mail, Canada, March 17, #71491

All about puzzles in newspapers, magazines, and books

### Globe and Mail, Canada, March 17, #71491

The solution to this puzzle appears to me not to be unique.

In the lower left 1 and 7 can be interchanged.
This propagates to the lower middle ( 1 and 7 interchanged) and then to the middle (1 and 7 interchanged).

Chris R

Posts: 2
Joined: 17 March 2006

Had the puzzle not given R6C9=7 and R7C9=1, then the puzzle would have two solutions, (known as a pseudo puzzles) as the 1 and 7 in rows 6 and 7 could be interchanged. Since there is a clue in one of these positions it forces the other cells to take a unique solution.

Original Clues
Code: Select all
` 7 . . | . . 1 | 4 . 9  . . 1 | 4 . . | . . .  9 . . | 3 8 . | . 1 . -------+-------+------  1 . . | . . . | 9 5 .  . . 6 | . . . | 2 . .  . 3 8 | . . . | . . 7 -------+-------+------  . 4 . | . 2 8 | . . 1  . . . | . . 4 | 6 . .  6 . 2 | 7 . . | . . 5 `

with solution:

Code: Select all
` 7 5 3 | 2 6 1 | 4  8 9  2 8 1 | 4 5 9 | 3  7 6  9 6 4 | 3 8 7 | 5  1 2 -------+-------+-------  1 2 7 | 8 3 6 | 9  5 4  4 9 6 | 1 7 5 | 2  3 8  5 3 8 | 9 4 2 | 1* 6 7* -------+-------+-------  3 4 5 | 6 2 8 | 7* 9 1*  8 7 9 | 5 1 4 | 6  2 3  6 1 2 | 7 9 3 | 8  4 5 `

hope this is of help
Crazy Girl

Posts: 189
Joined: 08 November 2005

Thanks!

I had copied out the puzzle on a separate sheet. I assumed, of course, that I had done so correctly! I had not filled in r9c4 with the clue 7.
Chris R

Posts: 2
Joined: 17 March 2006