# Monday Puzzle #3: "Circular Reasoning"

Discussion in 'Miscellaneous' started by Jadzia, Aug 3, 2009.

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And kia is correct.

edit +3.5 hours : Laren is correct too

Last edited: Aug 4, 2009
2. ### kathryn i amRear AdmiralRear Admiral

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Yay!!

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Okay, the fourth one nearly made my brain ooze out of my ears...

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I'm not going to play this time.

I don't like this sort of logic-based/number-crunching puzzle. Anyone can force an answer from the information provided, by running through a series of rules and testing which fails. That kind of puzzle is best done by machines.

I much prefer the lateral-thinking detective type of puzzle. Or, if you like, crosswords to sudoku.

5. ### Zulu RomeoWorld Famous Starship CaptainAdmiral

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You will love next week's.

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I can hardly wait.

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Often easier said than done.

It is good that anyone can answer it. It makes it a balanced and accessible question. The skill is in coming up with an effective method for solving it. This makes the problem solving as intuitive and holistic as it is logical and analytic.

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Point taken.

Well, put more simply, I just don't find this kind of problem solving enjoyable to do.

Puzzles should not be fair. They should be grossly UNfair, requiring a rare and unique moment of incisive inspiration to solve and make it all suddenly clear. Puzzles that are fair are not puzzles, they're maths or logic PROBLEMS. I don't do problems for fun.

9. ### Zulu RomeoWorld Famous Starship CaptainAdmiral

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I'll see you next week.

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And trampledamage becomes our sixth winner. Well done to you.

11. ### All Seeing EyeAdmiral

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I'll post in thread since the thread is now over.

This puzzle makes no sense for the following reason:

Ok so a yellow must be either circle or triangle because they are never square.

So a yellow object cannot be rough because a yellow object can only be a circle or triangle.

Only squares can be rough, therefore they're not circles and therefore from what you say must be yellow.
But you've said (in the top quote of this post) that yellow shapes are never square.

So this makes no sense at all. It contradicts itself.

How anyone got the answer is beyond me.

12. ### kathryn i amRear AdmiralRear Admiral

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I don't think the thread has quite run its course yet, Tachyon Shield... the answer is normally given on Friday.

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Not until friday.

Your reasoning is unsound.

14. ### All Seeing EyeAdmiral

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oh sorry I thought thread was over. I saw the last post said "such and such is correct" so I thought the winner had been named.

Sorry.

It still don't make sense though.

15. ### Zulu RomeoWorld Famous Starship CaptainAdmiral

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That's the great thing about this contest. There's a winner, but the contest goes on until the last one is dead.

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Okay, well I might as well give some general help with the puzzle.

Contradiction is a valid tool in reasoning, and arguably the most important. When you chain several logical statements together, it is common to create contradictions with values of some the variables, and that says something important about those variables -- specifically values which cannot appear in any solution.

So for example, if one statement said "blue objects are always hexagons" and another said "hexagons can never be blue", then you can deduce that "blue objects cannot be blue".

This is not a contradiction of the "colour" variable, but is a contradiction of a specific value of the colour variable. This simply means that the colour variable cannot take the value of "blue" in any solution to the problem.

If there are no blue objects, then rules about blue objects are arbitrary and become irrelevant.

Last edited: Aug 5, 2009
17. ### trampledamageCloneModerator

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It's the various contradictions that make it possible to solve

18. ### All Seeing EyeAdmiral

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Well i'm beat, my head hurts with it so I give in.

19. ### kathryn i amRear AdmiralRear Admiral

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This is a very big clue

20. ### NickInABoxCaptainCaptain

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::Tents fingers::

I like the direction the ____ Quiz is going.