dailysudoku.com

[igolf4birdies]

I had printed out some older puzzles to work and have gotten stuck on this one. It is rated as "hard" but I must be missing something. It seems "very hard" to me.

Can someone please give me some logic. Here is where I am.

8 _ 7 _ 2 5 3 9 1
2 1 _ _ _ 3 4 5 8
_ 5 3 _ _ _ 7 6 2
_ _ _ 5 1 _ _ _ 7
1 _ _ _ 4 _ _ _ 9
7 _ _ _ 3 8 _ _ _
5 9 _ _ _ _ _ 8 3
_ _ 2 3 _ _ _ _ _
3 _ 1 _ 5 _ 9 _ 4

I have found (7,8) pair in r8c2 and r9c2 and a (5,8) pair in r5c3 and r5c7. But stuck from there.

Thanks in advance.
Rick

[David Bryant]

Hi, Rick!

You need to concentrate on the bottom center 3x3 box, and on row 9 in particular.

-- You have already found a "hidden pair" {7, 8} in r7c2 & r9c2. So there can't be a "6" at r9c2.

-- There can't be a "6" at r9c8 either, because of the "6" at r3c8.

-- So the "6" in row 9 must lie in the bottom center 3x3 box, at r9c4 or at r9c6, and you can eliminate "6" from the other empty cells in the bottom center 3x3 box.

-- In particular this means that r7c5 = 7 -- that should get you rolling again. dcb