Search found 21 matches

by kansasdave
Sat Dec 21, 2013 1:52 pm UTC
Forum: Serious Business
Topic: Encode a message so it can't be read until a certain time?
Replies: 84
Views: 55287

Re: Encode a message so it can't be read until a certain tim

Build a monolith that will let light through in the pattern you want when the sun is in the right position in the sky.

Offer to set up a time capsule for an elementary school, then hide it with the kids messages for the future. Nobody will bother looking early.
by kansasdave
Thu Nov 14, 2013 10:04 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1289: "Simple Answers"
Replies: 50
Views: 11489

Re: 1289: "Simple Answers"

"'Will [ ] allow us to better understand each other and thus make war undesirable?'"


Optimistic "thus."
by kansasdave
Sun Jun 12, 2011 3:44 pm UTC
Forum: Coding
Topic: Logic Puzzle Solver
Replies: 1
Views: 2079

Logic Puzzle Solver

I have a coding question related to a personal project I have to build a logic puzzle solver for grid-based logic puzzles. To see a lot of examples of this kind of puzzle, look here: http://www.logic-puzzles.org/ First, some background: Let 'n' represent the number of categories in a logic puzzle, a...
by kansasdave
Mon Jun 06, 2011 2:55 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0904: "Sports"
Replies: 128
Views: 30137

Re: 0904: "Sports"

by kansasdave
Mon Nov 15, 2010 10:35 pm UTC
Forum: Logic Puzzles
Topic: A very interesting Mathematical Paradox
Replies: 387
Views: 157993

Re: A very interesting Mathematical Paradox

Two numbers are equal if their difference is zero. How does this apply when one of the numbers is something weird with infinite non-zero digits, like 0.99999....? The way math guys usually deal with things like this is to say that 0.99999... is equal to 1 if, no matter how small a separation you giv...
by kansasdave
Fri Dec 04, 2009 6:26 am UTC
Forum: Logic Puzzles
Topic: 12 Craziest Google Interview Questions
Replies: 67
Views: 13665

Re: 12 Craziest Google Interview Questions

7. Assuming companies merge in pairs, and order matters: To save space, C(X,Y) = X Choose Y = X! / (Y! * (X-Y)!) First pair of companies can be chosen in C(N,2) ways 2nd pair of companies in C(N-1,2) ways (choosing 2 from the set of all N-2 remaining compa...
by kansasdave
Fri Apr 17, 2009 5:44 am UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma
Replies: 833
Views: 88495

Re: Traveler's Dilemma

lordatog wrote:And you still didn't answer my question.


Sorry not to have been clear.

$2 < $100
by kansasdave
Fri Apr 17, 2009 5:10 am UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma
Replies: 833
Views: 88495

Re: Traveler's Dilemma

The step in the "100 is optimal" strategy I have a problem with is the line "Given that you and your opponent are both going to pick the same number, which number is optimal?" That line implies that you can influence your opponent's choice by way of your choice but you can't. Of...
by kansasdave
Fri Apr 17, 2009 4:15 am UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma
Replies: 833
Views: 88495

Re: Traveler's Dilemma

Clearly you disagree with the above. What I really don't know is precisely which step you have a problem with. Let's suppose again that there is a unique, optimal strategy, X, and that you and your opponent are both perfectly rational, and both going to pick your numbers via strategy X. Fine. Given...
by kansasdave
Thu Apr 02, 2009 3:18 am UTC
Forum: Logic Puzzles
Topic: Self-Referential Aptitude Test
Replies: 1
Views: 1767

Self-Referential Aptitude Test

A friend just recommended this to me. I haven't solved it yet, but have been assured that there is a unique solution. SELF-REFERENTIAL APTITUDE TEST, by Jim Propp (propp@math.wisc.edu) The solution to the following puzzle is unique; in some cases the knowledge that the solution is unique may actual...
by kansasdave
Wed Apr 01, 2009 9:06 pm UTC
Forum: Logic Puzzles
Topic: The Sexaholics of Truthteller Planet
Replies: 15
Views: 2818

Re: The Sexaholics of Truthteller Planet

Well done!

Now, can you decode a word or phrase from your solution? There's a hint in the flavor text.
by kansasdave
Wed Apr 01, 2009 11:08 am UTC
Forum: Logic Puzzles
Topic: Three princesses
Replies: 446
Views: 206863

Re: Three princesses

Greyson wrote:But you might ask the middle child.


Spoiler:
Asking the middle child isn't a problem. If you ask the middle child (so she's A) then neither of the princesses you might marry (B or C) is the middle princess.
by kansasdave
Wed Apr 01, 2009 10:53 am UTC
Forum: Logic Puzzles
Topic: The Sexaholics of Truthteller Planet
Replies: 15
Views: 2818

Re: The Sexaholics of Truthteller Planet

This doesn't affect the day 1 analysis, but is it correct to assume that if an individual is infected, they remain infected over the course of the puzzle, and if an individual is uninfected, they remain uninfected over the course of the puzzle? Yes; that was specified in the original post (which is...
by kansasdave
Wed Apr 01, 2009 2:46 am UTC
Forum: Logic Puzzles
Topic: The Sexaholics of Truthteller Planet
Replies: 15
Views: 2818

The Sexaholics of Truthteller Planet

This puzzle is from the 2009 MIT Mystery Hunt. It's the hardest example of this kind of logic puzzle I've ever seen. Check out this link for more 2009 Hunt puzzles: http://web.mit.edu/puzzle/www/09/puzzles/ Any other Hunters out there? Anyway, here's the puzzle. Note that as with most Hunt puzzles, ...
by kansasdave
Tue Mar 31, 2009 3:47 am UTC
Forum: Logic Puzzles
Topic: Word Chain
Replies: 86
Views: 9921

Re: Word Chain

Zak wrote:Edit: Whoops, just realized that that was from the first page...
Spoiler:
Waffle -> Sand?
Waffle -> Debris -> Free -> Gratis -> Grit -> Sand
Synonym, sounds like, translate (spanish), sounds like
Erm,
Glass -> Fly


Spoiler:
glass
pane
pain
sore
soar
fly
by kansasdave
Tue Mar 31, 2009 3:20 am UTC
Forum: Logic Puzzles
Topic: Three princesses
Replies: 446
Views: 206863

Re: Three princesses

Spoiler:
Ask A: 'If asked, would you confirm that B is the middle princess?'

If B is in fact the middle princess, the eldest and youngest would both say 'yes.' If B is not the eldest, they would both say 'no.' Marry C if you get a 'yes' and B if you get a 'no.'
by kansasdave
Sun Mar 29, 2009 2:49 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma
Replies: 833
Views: 88495

Re: Traveler's Dilemma

I think that they would both reason like this: Aha! I've seen this before.This is one of those puzzles where a series of seemingly optimal choices leads us to get almost nothing. If I know that, so must my traveling companion. We're going to come to the same conclusion about either playing this ruin...
by kansasdave
Sun Mar 29, 2009 2:35 pm UTC
Forum: Logic Puzzles
Topic: Three princesses
Replies: 446
Views: 206863

Re: Three princesses

Ask A: "Is it true that A is the eldest and B is the middle, or that A is the youngest and B is the eldest?" Case: A eldest, B middle: answer is true, A says 'yes' Case: A youngest, B eldest: answer is true, A says 'no' Case: A eldest, B youngest: answer is false, A says &...
by kansasdave
Sun Mar 29, 2009 6:39 am UTC
Forum: Logic Puzzles
Topic: Describing numbers...
Replies: 65
Views: 20305

Re: Describing numbers...

The answer is either '1' (though it could be expressed in 'fewer' than seventeen words in standard English) or 'no answer' if we replace 'less' with 'fewer' because were such a number to exist, the phrase: 'The smallest natural number that cannot ...
by kansasdave
Sun Mar 29, 2009 5:56 am UTC
Forum: Logic Puzzles
Topic: Three princesses
Replies: 446
Views: 206863

Re: Three princesses

Right. Ask A whether B would say C is the youngest. If you're asking the eldest and C is the middle, she'll say 'yes'; if you're asking the youngest and C is the middle, she'll say 'yes.' So ask the question, if you get a 'yes' marry B, and if you get a '...
by kansasdave
Sun Mar 29, 2009 5:39 am UTC
Forum: Logic Puzzles
Topic: Three princesses
Replies: 446
Views: 206863

Re: Three princesses

You ask: "Is the middle princess going to answer this truthfully, or are you the youngest princess? If asked to the eldest, the true answer is 'no,' so she says 'no.' If asked to the youngest, the true answer is 'yes,' so she says 'no.' If asked to the middle pr...

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