View Full Version : How to Solve a Logic Puzzle

admin

01-29-2014, 12:44 PM

We've put together a new, in-depth tutorial that covers all the basics of grid-based logic puzzles, as well as many intermediate- and advanced-level solving techniques. Any feedback on the tutorial would be greatly appreciated.

The tutorial can be found here:

http://logic-puzzles.org/how-to-solve-a-logic-puzzle.php

Thanks!

Alethea

01-29-2014, 01:41 PM

These tutorials are a great idea - they explain so much more in depth than it's possible to do with just the hints. Clicked around the various subheadings and through their steps, and everything seems to be functioning perfectly so far.

stanstar

01-30-2014, 02:36 AM

Hi admin I am sorry to point out that the description in Either or clues slide #3 is wrong and misleading. I post what it says here: Slide #3

Just like the "neither/nor" clue, an "either/or" clue implies that the two items (Laura and $40) being discussed in relation to the third (Pisces) are separate entities. The Pisces can be either Laura's tattoo or the one that cost $40 - we don't know which of the two it is, but we know it definitely cannot be both.

Therefore we know that Laura's tattoo didn't cost $40, and we can mark an X on the grid where those two options intersect.

I will highlight the misleading part.

In my opinion it should read as follows: The Pisces can be Laura's tattoo or NOT Laura's tattoo, and the $40 is Laura's tattoo or NOT Laura's tattoo. Therefore The PISCES tattoo and the $40 are false. That is all the deduction we can infer.

Stan

admin

01-30-2014, 05:43 AM

Thanks Stan! You're absolutely right - the text for that slide is fixed now.

stanstar

01-30-2014, 05:54 AM

No problem Admin ;)

IMO the rest of the help makes sense to me. No other misleads. No charge for proof reading.

Stan

PS Now I am going to try to beat my record time of 19mins for a 4x5 challenge type.

BillsBayou

01-30-2014, 10:57 AM

"Comparative Relationships" Slide #4: If Wilma's tattoo is $10 more than the red one

That should read: If Wilma's tattoo is $10 LESS than the red one

BillsBayou

01-30-2014, 11:02 AM

"Transitive Relationships (Either/Or)" Slide #1

Since $40 is already false for Isaac, it must be true for orange. Get rid of that "X" and the tutorial plays out correctly.

stanstar

01-30-2014, 11:08 AM

Hi Bill you are correct Sir. You have a keener eye than mine. I also spotted while checking that in the same explanation it incorrectly says that gemini is greater than Red instead of lesser than red.

Here it is:

If Wilma's tattoo is $10 more than the red one, and the Gemini tattoo is $5 more than the red one, then Wilma's tattoo can't be equal to the Gemini tattoo. They are both different "distances" away from the same item ("red tattoo") in relation to price - therefore they are different entities.

Stan

BillsBayou

01-30-2014, 11:25 AM

"Transitive Relationships (Unaligned Pair)"

I'd like to see more on the power of Unaligned Pairs. While your example does a good example of showing the transitive relationship as a solving method, Slide #7 does a poor job of showing off cross eliminations.

In an Unaligned Pair clue such as the one given, the intersection of "Zachary" and "Aquarius" become the center of a cross elimination that affects "Blue" and "$40". That box is "Sign-Name". For all Names eliminated by "Aquarius" and all Signs eliminated by "Zachary", neither "Blue" nor "$40" can be those values.

Thus "Zachary/Aquarius" points to "Bonita" and "Taurus". Eliminate both "Bonita" and "Taurus" from the possible values of "Blue" and the possible values of "$40".

If you weren't pointing out the transitive technique, you could have used cross eliminations by showing that "Blue/$40" points to "Orange", "Violet", "$45", $50", "$60", and eliminate those 5 values from each of "Zachary" and "Aquarius".

admin

01-30-2014, 12:03 PM

"Comparative Relationships" Slide #4: If Wilma's tattoo is $10 more than the red one

That should read: If Wilma's tattoo is $10 LESS than the red one

Absolutely right - fixed it now, thanks!

admin

01-30-2014, 12:06 PM

"Transitive Relationships (Either/Or)" Slide #1

Since $40 is already false for Isaac, it must be true for orange. Get rid of that "X" and the tutorial plays out correctly.

Good catch - I'll have to redo that portion of the tutorial with something that doesn't immediately solve the either/or clue.

Quazar

01-30-2014, 01:16 PM

Hi, I'm back after taking a break and l-p.org has never looked better, nice job! I noticed this thread and thought I'd give the new content a look -- fantastic!

I did notice a section you might want to revisit, Parallel Cross Eliminations. Slide #1 introduces the terms geometrical and non-geometrical, explains clearly in 5 slides about geometrical, gives the reader a chance to spot one, and ends on slide #7 with "let's roll up our sleeves and try the slightly harder non-geometrical cross-eliminations." Seems to be missing slides #8-n discussing this technique?

passel3

01-30-2014, 01:58 PM

Pseudo-True Pairs (Aligned)

In Slide #3, you correctly say "to uncover four new false squares"

In Slide #4, you incorrectly say "Therefore we can mark five new false ..."

In Slide #4 you take credit for X'ing off (January,Wood), but in all previous slides (January,Wood) was already X'd off.

passel3

01-30-2014, 02:08 PM

...I did notice a section you might want to revisit, Parallel Cross Eliminations. Slide #1 introduces the terms geometrical and non-geometrical, explains clearly in 5 slides about geometrical, gives the reader a chance to spot one, and ends on slide #7 with "let's roll up our sleeves and try the slightly harder non-geometrical cross-eliminations." Seems to be missing slides #8-n discussing this technique?

My initial take on that was it was a lead-in to the next lesson, called Skewed Cross Eliminations.

Which would mean that geometrical would refer to Parallel, and non-geometrical would refer to Skewed.

passel3

01-30-2014, 02:44 PM

Good catch - I'll have to redo that portion of the tutorial with something that doesn't immediately solve the either/or clue.

Since we don't have the other clues or can relate this to a known puzzle, it would seem just removing the X from $40/Isaac, as BillBayou suggested would fix the tutorial without reworking the tutorial, other than possibly having to mentioning Isaac as not being $40 (along with Wilma and Zachary) if $40 is orange.

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