## Search found 637 matches

Fri Jan 27, 2012 6:00 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1009: "Sigh"
Replies: 111
Views: 38839

### Re: 1009: "Sigh"

Wow. Randall, I don't know what these people are on about, I thought it was hilarious. As my wife loves both Downton Abbey and the song (thanks to this Boston Terrier-themed video ), I plan to attempt this IRL, next time it's on TV. If it helps, "Sexy and I know it" (the referenced LMFAO s...
Wed May 25, 2011 3:03 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0903: "Extended Mind"
Replies: 666
Views: 185057

### Re: #903: Extended MInd

Dang, I just can't seem to reach philosophy. I keep getting trapped in the Greek Loop, as I've come to call it. Actually, even the "Greek loop" kind of gets there: Ancient Greek Greek Language Indo-European Language family Language Communication Meaning ( philosophy of language) Definitio...
Wed Jul 21, 2010 3:00 pm UTC
Forum: Logic Puzzles
Topic: Chess problem: The missing king
Replies: 60
Views: 11467

### Re: Chess problem: The missing king

There can't be any strange trick with the knights - a knight must always change the color of his square on a move, so if the knights are on (white, black) to start, and (white, black) to end, the total number of knight moves must have been even.
Wed Jun 09, 2010 2:12 pm UTC
Forum: Logic Puzzles
Topic: The two boat races
Replies: 18
Views: 3220

### Re: The two boat races

Right, you can think of it this way:

Spoiler:
Can a sailboat, on a lake, move to a point directly upwind?

The answer is, of course, yes, and this also means that it can move faster than the current, with a "headwind".
Wed May 26, 2010 2:19 pm UTC
Forum: Forum Games
Topic: Word Puzzle
Replies: 114
Views: 16072

### Re: Word Puzzle

PODIUM
Tue May 25, 2010 2:12 pm UTC
Forum: Logic Puzzles
Topic: A "I-Don't-know-what-to-call-it" puzzle
Replies: 4
Views: 1702

### Re: A "I-Don't-know-what-to-call-it" puzzle

Are there other puzzles that led you to this point? Any sort of context that would help us out?
Mon May 10, 2010 6:21 pm UTC
Forum: Logic Puzzles
Topic: The Email Cipher
Replies: 10
Views: 2599

### Re: The Email Cipher

Clever. I like it. Wish I had been able to solve it on my own.
Thu May 06, 2010 5:24 pm UTC
Forum: Logic Puzzles
Topic: Palindromic Odometer
Replies: 19
Views: 3635

### Re: Palindromic Odometer

Wait a minute...

Spoiler:
Do all the digits of the odometer work correctly?

If some of the number wheels aren't working right, there are potentially a number of ways this could be true.
Thu May 06, 2010 4:07 pm UTC
Forum: Logic Puzzles
Topic: Palindromic Odometer
Replies: 19
Views: 3635

### Re: Palindromic Odometer

Hmm... I'm not sure I understand it, then. You traveled one kilometer, so the ones digit of the number increments. For the number to remain a palindrome, the most significant digit must then also increment. The only way this can occur is if the ones digit is incrementing from 9 to 0 (and therefore s...
Tue May 04, 2010 4:26 pm UTC
Forum: Logic Puzzles
Topic: The Email Cipher
Replies: 10
Views: 2599

### Re: The Email Cipher

Wild speculation: There are 31 letters (not counting spaces) in the plaintext, and 31 numbers in the string. There are 32 words in the email. So possibly the numbers go "in between" the words, and combining the number somehow with the words on either side of it generates the plaint...
Fri Apr 30, 2010 8:33 pm UTC
Forum: Logic Puzzles
Topic: An Alien Code?
Replies: 16
Views: 4043

### Re: An Alien Code?

Yeah, I'm pretty sure I have a good idea of what is going on here, I just have to figure out the rest of the system...

Yep.

Spoiler:
DESTROY ALL HUMANS
Fri Apr 23, 2010 4:42 pm UTC
Forum: Logic Puzzles
Topic: Petals Around the Rose
Replies: 2
Views: 1598

### Re: Petals Around the Rose

Original thread here.
Wed Apr 21, 2010 5:15 pm UTC
Forum: Logic Puzzles
Topic: Cipher: the story of two rivals
Replies: 8
Views: 2500

### Re: Cipher: the story of two rivals

Oh, wow.

I spend more time thinking about that 100 than you can possibly believe, and the answer was right in front of me the whole time...
Tue Apr 20, 2010 6:23 pm UTC
Forum: Logic Puzzles
Topic: Cipher: the story of two rivals
Replies: 8
Views: 2500

### Re: Cipher: the story of two rivals

Question: Is there some correlation between the numbers and the letters they encode? Or is this a random mapping you just made up? The hints are possibly useful, but none of them really seem to deal with the letter-number relationship, which means we're still looking at a substitution cipher wit...
Fri Apr 16, 2010 2:33 pm UTC
Forum: Logic Puzzles
Topic: Given that you have a brother...
Replies: 41
Views: 7751

### Re: Given that you have a brother...

I toss 10 fair coins. Is it reasonable to say that there will be exactly 5 heads and 5 tails? If I hide one of the coins and look at the other 9, does that change the probability that the hidden coin is heads? Like Skep says, it's the gambler's fallacy. The chance for a specific individual is 50/50,...
Mon Apr 12, 2010 2:18 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

Yeah, that's mentioned on the first page. We've moved past that, to the point of discussing what happens if Monty doesn't actually know where the car is, and why that has different odds from the classical scenario.
Fri Apr 09, 2010 8:35 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

Right, it's exactly the same as the probability that you chose correctly in the first place. 1%. But once it HAS happened, you have more information than you did in the beginning. The point of the problem was to illustrate that it DOES matter whether or not Monty knows where the car is. Once you hav...
Fri Apr 09, 2010 7:18 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

It doesn't change the fact that you had a 1% chance originally. But given what you know now, the chance has improved considerably. You pick 1 of 100 doors. What odds do you need me to offer you, for you to bet that you have guessed correctly? You peek in 50 of the other doors and there is no car. No...
Fri Apr 09, 2010 6:05 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

I didn't say Vanna, Monty, or Zaphod. YOU choose which 98 doors are revealed. It so happens that none of them contained a car. This, of course, is not very likely. But if it happens, do you really believe that the door you picked originally is somehow worse than the one you haven't picked? What if a...
Fri Apr 09, 2010 5:10 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

If Monty is picking randomly, and reveals a goat, then it does not matter whether you switch. There is now a 50% chance that the car is behind the door you picked originally. People keep mentioning farm animals and I'm not sure why. Are we looking at two different puzzles? In the puzzle I explained...
Fri Apr 09, 2010 2:10 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

But you've still arrived at the wrong conclusion.

If Monty is picking randomly, and reveals a goat, then it does not matter whether you switch. There is now a 50% chance that the car is behind the door you picked originally.
Thu Apr 08, 2010 6:10 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

Why are there so many opinions about this? The logic is pretty simple. At the start of the game you choose 1 of 3 doors. Your chance of choosing the door with the car behind it is 1/3 or 33% (rounded). Monty then picks a door. It doesn't matter if he knows where the car is or not. If he randomly pi...
Wed Apr 07, 2010 8:25 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

Of course, in the real world, there is no way for you to know whether the host knows what's behind the door he chooses or not. If he does, then you must switch; if he doesn't, then you lose nothing by switching. So you're better off switching based on the possibility that the host knew not to show y...
Wed Mar 24, 2010 3:53 pm UTC
Forum: Logic Puzzles
Topic: MU puzzle from GEB
Replies: 5
Views: 5110

### Re: MU puzzle from GEB

But the bottom part of your post is essentially a proof. I mean it's not written all formal-like, but you've convinced yourself that there's no way to get rid of all the I's... if you just say it with more certainty, that's essentially a proof. The only part you need to really flesh out is proving t...
Thu Mar 18, 2010 9:51 pm UTC
Forum: Logic Puzzles
Topic: A few codes
Replies: 8
Views: 1712

### Re: A few codes

Last one:

Spoiler:
This is the hardest keyboard code yet.

Do you feel better now, V?
Tue Mar 16, 2010 9:31 pm UTC
Forum: Logic Puzzles
Topic: Camalot Drinking Game
Replies: 9
Views: 1811

### Re: Camalot Drinking Game

edit - Nitrodon in for the win. But some of the below may be instructive in how NOT to approach the problem. It works, but it's trial and error in a sense - Nitrodon's approach is elegant. Also, I was really hoping this was going to be a game involving alcohol and Monty Python. For a simple adjustme...
Tue Mar 16, 2010 8:46 pm UTC
Forum: Logic Puzzles
Topic: Help with a coded question
Replies: 4
Views: 1277

### Re: Help with a coded question

Heh, this might be interesting. I use a python script to do letter substitution for simple sub ciphers, and it left me with a nice record of my process in working through the decryption. Spoilered for length: ay ay a ay ay ay ay a ay ay ay ay? EOFTH EMMARRITH TOTH EDWITH EBOTH ANTH TBROTH EWASITH AL...
Tue Mar 16, 2010 6:26 pm UTC
Forum: Logic Puzzles
Topic: Shoot out (easy)
Replies: 4
Views: 1476

### Re: Shoot out (easy)

I've heard a variant on this where A is a perfect shot, B is good but not perfect, and C is bad. This version is simpler, but the idea is the same.
Tue Mar 16, 2010 5:03 pm UTC
Forum: Logic Puzzles
Topic: Help with a coded question
Replies: 4
Views: 1277

### Re: Help with a coded question

Don't strip out the TH - use it! You've got some letters to go on, now. A little old fashioned letter substitution work yields: Who dropped a rock on me and broke the conch? The key word for cracking the cipher was EMMARRITH. Figuring out the patterns of double letters in that one, plus the question...
Mon Mar 15, 2010 8:31 pm UTC
Forum: Logic Puzzles
Topic: Monty Hall Problem
Replies: 116
Views: 53129

### Re: Monty Hall Problem

The explanation that I've been able to convince people with is: <Give them 3 doors, say they select door 1> Now, do you want what's behind door number 1, or what's behind Doors 2 and 3? They'll protest, but you can then show them that if the prize is behind Door 2, their switch will always be to Doo...
Thu Mar 04, 2010 3:17 pm UTC
Forum: Logic Puzzles
Topic: complete the sequence; too easy? too hard? too dumb?
Replies: 9
Views: 2429

### Re: complete the sequence; too easy? too hard? too dumb?

I'll give a helpful-but-not-too-helpful hint:

Spoiler:
The sequence ends after a finite number of terms.
Wed Mar 03, 2010 10:16 pm UTC
Forum: Logic Puzzles
Topic: complete the sequence; too easy? too hard? too dumb?
Replies: 9
Views: 2429

### Re: complete the sequence; too easy? too hard? too dumb?

It's funny the directions different people's brains go when trying to find the answers to a puzzle like this. The issue is that solving these things essentially consists of trial and error, and there's absolutely no way to figure how long it's going to take people without knowing your audience well ...
Wed Mar 03, 2010 7:13 pm UTC
Forum: Logic Puzzles
Topic: complete the sequence; too easy? too hard? too dumb?
Replies: 9
Views: 2429

### Re: complete the sequence; too easy? too hard? too dumb?

Spoiler:
3, 6, 2....
Tue Feb 23, 2010 6:17 am UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

If you pick anything other than \$100, future rounds of the game devolves into a race to the bottom, dominant strategy of \$2. But if you're allowed to signal to the other player (ie, by playing the previous round and picking \$100), you end up with 100*(number of rounds). The reason people pick \$100 ...
Fri Feb 19, 2010 10:35 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

I posit that the reason for most of our 100-pickers is "not playing strictly to maximize gain" - but that's exactly what makes this discussion so fascinating to me.
Thu Feb 18, 2010 11:16 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

Yeah, but you'd lose that bet. Any alteration of my strategy based on my opponent would have nothing to do with the thought that the opponent can glean some information from watching me. This is fundamentally different from a poker game - in poker, the amount you are willing to bet conveys some info...
Thu Feb 18, 2010 8:22 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

But if you are confident that the other player will pick 100, and you're trying to maximize your winnings, you will pick 99, not 100. \$100 is just as wrong as \$2, and in my estimation more wrong, because there is another play that will always net you equal or greater winnings regardless of what your...
Tue Feb 16, 2010 3:09 pm UTC
Forum: Logic Puzzles
Topic: How Many Legs Are On The Bus
Replies: 12
Views: 2519

### Re: How Many Legs Are On The Bus

Spoiler:
No one said that the little cats were on the bus, simply that for every big cat there are 7 little cats (in the world).

However it is highly unlikely that there are no flies on the bus.

I hate this puzzle, there's about 4 layers of ambiguity.

http://xkcd.com/169/
Fri Feb 12, 2010 10:43 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

thing is, domination isn't everything. \$2 is the most dominating number, but will almost certainly get you a much lower return than otherwise - as covered way too much on this thread, the logic is flawed. No, the logic isn't flawed. The logic applies under a specific set of assumptions and does not...
Fri Feb 12, 2010 3:48 pm UTC
Forum: Logic Puzzles
Topic: Traveler's Dilemma: What would YOU do?
Replies: 166
Views: 19404

### Re: Traveler's Dilemma: What would YOU do?

I like the way you think. I suppose that 100 could be considered an optimal play in the sense that it's the most likely play to extract the maximum amount of money from the airline (that is, if you pick 100, and the other player picks either 99 or 100, then the airline loses \$200 - whereas if you pi...

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