

Rather crazy online logic test - brl
http://drunkmenworkhere.org/170

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brl
This kind of reminds me of the 'Mr. P and Mr. S' puzzle.

In case you don't know it, there are two numbers (m,n) between 1 and 100. Mr.
P is told the product (m * n) and Mr. S is told the sum (m + n), but neither
is told the original numbers.

Then they have a conversation that goes like this:

Mr. P: I don't know what the numbers are.

Mr. S: I knew you didn't know them. I don't know them either.

Mr. P: Oh, now I know what they are!

Mr. S: Me too! I know too!

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jrp
Djikstra's reply is pretty cool:
<http://www.cs.utexas.edu/users/EWD/ewd06xx/EWD666.PDF>

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rjprins
I just solved it in 1,5 hour without using pen and paper at all! But then, I
didn't prove it was unique and was kind of lucky the solution was small...

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unalone
This is fascinating! I love that the solution requires balancing every answer
with every other answer, so that at time it appears nearly solved but one
offset number ruins everything else.

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newt0311
The trick is to slowly narrow the choices. After the narrowing, you can start
making simplifying assumptions and see if these assumptions are self-
consistent with the test. Like a sudoku, but not boring and trivial.

~~~
jyothi
I just read it out too. Amazing creation as a whole.

The toughest thing was i could not scratch out the 'not-possible' options to
think more clearly. I took me a little more than an hour.

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gruseom
What a great idea. It may take all my strength to resist getting sucked in,
damn you! And I was just telling someone how refreshingly boring Hn has been
lately.

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jcl
Here's a collection of links about the puzzle, including various methods of
solution and other self-referential puzzles (the author's link in the article
is broken):

<http://faculty.uml.edu/jpropp/srat.html>

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bena
It's an exercise in inductive reasoning to say the least.

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tlrobinson
So who's going to write a Prolog program to solve this?

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gambling8nt
This is unnecessary; the solution is fairly straightforward, although it would
have been more elegant if the problem constrained question 20 better.

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tlrobinson
Yeah, but that's no fun ;)

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whatusername
wow - I've got the first few easy ones - but that's getting pretty insane..

How long does it take people to finish?

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artlogic
Took me about an hour or so using only logical reasoning - no guessing.

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newt0311
This is fun. When you are done solving it. Try separating the answers into
words. You should end up with an interesting sentence.

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bena
I just read that. Wow. That must have taken a while.

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newt0311
~30 mins. Its really a game of organization and considering the possibilities.
I think the SRAT should replace IQ tests and the SAT. Just have a set of these
in increasing levels of difficulty and grade people by which ones they manage
to solve.

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rms
It's still only testing the ability to perform a particular test. Intelligence
is so much broader and is only generally correlated with these types of logic
tests.

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newt0311
Still a massive improvement over the SAT et al. At least we have _some_
correlation.

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rms
You don't think there is any correlation at all with the SAT and intelligence?
Come on.

