macl Daily subscriber Rated puzzle: Easy Best completion time: 1:23:21 Time on first attempt: 10:13:02 Used 'check puzzle' when incorrect

I found an alternative solution?

Posted 23rd Feb 2014 at 01:26

gareth Administrator Daily subscriber Rated puzzle: Hard Completion time: 22:28 Used 'remove'

There's certainly only one solution to this puzzle. Every puzzle on PuzzleMix, without any exceptions, has a single, unique solution.

This particular puzzle involves a few x-wing deductions, and a 'naked set' of 4 (or a 'hidden set' of 3 if you prefer), so is pretty tricky - but it can be solved without guessing which means you can prove to yourself that the given solution is the only one.

And if you can't see what's wrong with your solution, turn on the inequality and repeated number solving aids - that will highlight errors.

Gareth, puzzlemix

Posted 23rd Feb 2014 at 11:31 Last edited by Elisabeth 23rd Feb 2014 at 18:40

Elisabeth Rated puzzle: Moderate Completion time: 26:12

I eventually found just one solution without having to guess. I spotted the x-wings but what is a 'naked set' of 4 / 'hidden set' of 3, please Gareth?!

On reflection I think it has to be if, say, only 1234 can be in 4 cells then they cannot be in the others, which in a 7x7 would therefore make the others 567....I have spotted this but didn't have a name for the situation! Am I right? I didn't find this an easy one but thought I was just not seeing something obvious:)

Posted 23rd Feb 2014 at 21:42 Last edited by gareth 23rd Feb 2014 at 21:46

gareth Administrator Daily subscriber Rated puzzle: Hard Completion time: 22:28 Used 'remove'

Hi, yes, that's a set. "Naked" means there are no other possible values in those cells; "hidden" means there are a set of x numbers that can only go in x cells but there are other candidates in those cells too, and so are harder to spot.

You can however view other players' statistics and their comments in the tables above.

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Key

A yellow/light blue highlight in the time distribution charts highlights your time, where relevant.

Rating scores out of 10.0 show the average difficulty rating chosen by users, where 1.0 is "Easy" and 10.0 is "Hard".

If a puzzle is opened more than once, including by loading from a saved position, then this is potentially a significant aid so it is listed as being completed with 'multiple sessions' for the purpose of the best time/average rating displays above.

Minor aid is defined as no more than one use of 'Check solution' when incomplete and/or no more than one use of 'Check solution' when wrong; and/or using highlighting aids (show repeated digits, show broken inequalities and show valid/invalid placements [slitherlink] only). Major aid is any and all other use of the solving aids except for 'show wrong'.

Add new comment)EasyBest completion time:1:23:21Time on first attempt:10:13:02Used 'check puzzle' when incorrectHardCompletion time:22:28Used 'remove'This particular puzzle involves a few x-wing deductions, and a 'naked set' of 4 (or a 'hidden set' of 3 if you prefer), so is pretty tricky - but it can be solved without guessing which means you can prove to yourself that the given solution is the only one.

And if you can't see what's wrong with your solution, turn on the inequality and repeated number solving aids - that will highlight errors.

Gareth, puzzlemix

Last edited by Elisabeth 23rd Feb 2014 at 18:40ModerateCompletion time:26:12On reflection I think it has to be if, say,

only1234 can be in 4 cells then they cannot be in the others, which in a 7x7 would therefore make the others 567....I have spotted this but didn't have a name for the situation! Am I right? I didn't find this an easy one but thought I was just not seeing something obvious:)Last edited by gareth 23rd Feb 2014 at 21:46HardCompletion time:22:28Used 'remove'Add new commentAdd a commentYour comment:You can however view other players' statistics and their comments in the tables above.

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