dailysudoku.com

[KSipher]

Hi
I'm learning so much from this forum, and am working old puzzles as practice. I'm stumped by this one - can someone explain the hint? Thanks so much!
Kathy

[KSipher]

Hi
Somehow the image of the puzzle didn't load, so I'll try again. Thanks for the help!
Kathy

[David Bryant]

Hi, Kathy!

If you look closely you'll find a "hidden pair" {4, 5} in column 3 -- specifically, in r2c3 and r8c3. So the only spot in row 2 where the "9" can possibly fit is at r2c4.

Oh -- I often find it simpler to find "hidden pairs" by concentrating on the numbers already entered in the grid than by examining lists of candidates. In this case the digits "4" and "5" appear in the middle left 3x3 box, and also in row 3. So it's fairly obvious that the pair {4, 5} has to appear in the only two cells in column 3 that can possibly hold those two digits. dcb

PS I'm not sure what causes the broken .gif. It works in some of my browsers, and not in others. If the image won't display, try right-clicking on the broken graphic symbol, then choose "view image".

[keith]

Kathy,

There is a triple <389> in C3. Once you clear the candidates from the other cells in the column, C4 is the only possible <9> in R2.

By the way, I have noticed that it takes some time after you post an image on Tinypic for it to work well in showing up in messages. If you want more instant gratification, use ImageShack (and use their first link for IMG).

I will revise the instructions on how to post an image after I have experimented with other image posting sites.

Keith

[KSipher]

Thanks so much for the replies and the hints. Once I found the hidden pair, the rest went quickly. I still have trouble finding hidden pairs or triples. I guess I just need more practice. The interface of draw/play is awesome. Fortunately I just retired from 33 years of teaching math, so I have lots of time to work these sudokus - it seems to be addicting. Thanks again!