Sudoku Puzzles

1) Start at 23 filled, the given puzzle. Unique Possibilities (UP) to 26.
2) np48, np37 => b3, f1, h3<>48; c3<>8; d12<>4; d56<>3, e78<>37 and f4<>7. UP66.
3)fc6's: b4=g4-g2=h3 => b3<>6. UP 81.

Or

1) Start at 23 filled, the given puzzle. Unique Possibilities (UP) to 26.
2) hp49 at df5, hp56 at d12 and hp48 at e38, UP66.
3) fc6's: b4=g4-g2=h3 => b3<>6. UP 81.

Just for Dahlia-nce.

A nice one for beginner.

Very easy until I got to the 3-5-6 conundrum. Then had to guess.
Terry

I couldn't get by the 3-5-6, either. I consider making a choice and "following a thread" to be guessing, so I felt "stuck" on this puzzle!

7:56 No challenge here.

Hi sotir,
For your solution of yesterday puzzle step 3 :
Almost np 89 at h12 used in a chain :
(2)h7=(2)h1-(89)h12=(8)g1-(8)g9=(8)c9-(8=4)c7 =>h7<>4. UP=81

It’s too simple to see invalid, chain A=B – C=D meant : if B is true => D is true
On yours :
1- if h7=2 More...

Pretty flower, had to guess to see it!

OK, all you sudoku fanatics... to see the photo easily, you just have to click on "play this pic as a jigsaw".... no guessing required.

Beautiful Dahlia, Sue.

10:22

To resolve 3,5,6 near the end:If h3=6,a1=6.However,going the other way,if h3=6,h5=3,c5=6,c8=3,a8=6 and a1=5,which contradicts.Therefore h3=5.

This is cool

Judy, borrowing clark's chain from his step 3 the logic in words goes like this: b4 is either 6 or it is not. if b4 is 6 then b3 is not. If b4 is not 6 then g4 must be, then g2 can't be and h3 must be 6 and once again b3 can't be 6. Therefore b3 can't be 6 and the rest is unique possibilities to the end.

11.06 That is the quickest I've done for a while.
Stunning Sue.
I got stuck on the 3-5-6 too!

Glad you're liking it Simo.

10.39
Still recovering from the Wintersun R&R festival. It was a long weekend to boot! Finding it hard to think this morning!

very quick on this one. to you all.

It just hit midnight here. Waiting to see if the line of thunderstorms require me to watch for tornadoes, but would prefer to go to sleep. Think it will be okay. Zzzzzz.

Thanks, Alfred and Jeff, for the help with the puzzle ... and for the encouragement.

Hope your still in the same place when you awake Plum. Nice one Sue.

Pleasant dreams Plum. And may they be Tornado Warning free. Those tornados can be mighty scary. I know... I once had one go right over me.

Hi All,

Another way to solve this one - only works if you have all bi-value squares left, except one - which is a tri-value. If you remove the common digit from the tri-value, you will finish up with an unsolvable puzzle (because it will have two ways to complete it). So, the common More...

This one seemed very easy for a tough - right up to the last few steps, when I had to guess, but luckily guessed right, so - my best time ever for this level! :)

I just cannot do a 'Tough'

Nice flower and nice to be back!!!

Heidi, we know.

Hi ttt,
Thanks for your comment and advise,but I cannot follow your logic:
1) Chain A=B-C=D =>A=D , not B=D.
2)If h7=2, =>h7<>4. It is clear.
3)If h7<>2,=>h1=2.It is also clear,but this does not mean that can conclude g1=8;The above chain
only conclude that More...

I was just happy to finish it.

26

Sotir,

Either there is a 2 in h7 or there is a 2 in h1.

A two in h1 prevents 8 and 9 from h1. However a 2 in h1 does not in anyway prevent either 8 or 9 in h2. Therefore you can not use the strong set (89)h12 to prove g1<>8.

Regards,

Dave

.......to prove g1=8, that is.

Stunning photo, Sue!

Hi sotir,
I did not say B=D, I said : if B is true => D is true
You misunderstand about “=” on chains, A=B meant : at least one of them is true
For : A=B – C=D, we are not much care in case A is true, we consider if A is false => B must be true then continue…

SE=4.2