## Search found 76 matches

- Fri Apr 30, 2010 10:43 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0734: "Outbreak"
- Replies:
**126** - Views:
**25837**

### Re: "Outbreak" Discussion

This is so unscientific. If it's a toxin, and manufactured to boot, it won't be going away for good. Just wait a few weeks and some evil scientist will have (re)developed it and will be using it for evil. The proper response is to build a better isolation chamber and start studying the zombie. FOR S...

- Mon Mar 03, 2008 1:50 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0391: "Anti-Mindvirus"
- Replies:
**377** - Views:
**76220**

### Re: "Anti-Mindvirus" Discussion

Wow, this discussion veered about 180 from where I thought it would go. I knew the people who read this comic are obsessed with Randall, but I didnt think they would view him as some divine power able to supersede an infinite loop of rules. The way I see it, either you rejected the game from the st...

- Mon Feb 04, 2008 3:10 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0378: "Real Programmers"
- Replies:
**201** - Views:
**53837**

### Re: "Real Programmers" Discussion

I think the real moral here is that only the guy using nano actually gets work done. Everyone else is just standing around talking about butterflies.

- Wed Jan 02, 2008 11:27 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0365: "Slides"
- Replies:
**45** - Views:
**10986**

### Re: 'Slides' discussion that I am merging

I suspect the people who "bare with you" are also the people who go "here, here". It's like the words themselves have no meaning anymore, and they just repeat a sound they heard.

- Mon Mar 19, 2007 10:42 pm UTC
- Forum: Logic Puzzles
- Topic: 3 door problem
- Replies:
**88** - Views:
**27289**

- Wed Mar 14, 2007 11:36 am UTC
- Forum: Logic Puzzles
- Topic: Firing Squad Synchronization
- Replies:
**18** - Views:
**8077**

- Wed Mar 14, 2007 12:30 am UTC
- Forum: Logic Puzzles
- Topic: The surprise exam paradox
- Replies:
**217** - Views:
**61820**

If it becomes Friday, the students go: A | B | C | D | E !A !B !C !D = E This is a valid deduction. On Thursday, it is shorter by one A | B | C | D | E !A !B !C = D | E The question is then if they are allowed to use their future knowledge (acquired on Friday) to conclude !E. Edit: I'm thinking some...

- Sun Mar 11, 2007 9:09 pm UTC
- Forum: Logic Puzzles
- Topic: Silly Prime Trivia
- Replies:
**16** - Views:
**5619**

Pssh, it is easy to show that the 3rd smallest uninteresting number will always be uninteresting. * 1st smallest is smallest uninteresting, and is therefore interesting. * 2nd smallest is smallest uninteresting, and is therefore interesting. * 1st smallest ceases to be interesting since it's no long...

- Wed Mar 07, 2007 4:36 pm UTC
- Forum: Logic Puzzles
- Topic: Silly Prime Trivia
- Replies:
**16** - Views:
**5619**

Factor 2 > not prime (even) Factor 3 > not prime (sum of digits) Factor 5 > not prime (5 or 0) Factor 11 > not prime (same digits) Square > not prime (rote memorization) This leaves us with factors 7 and 13, since we see that 7*17 = 119 is too big. The only possible number remaining is thus 7 * 13 ...

- Fri Mar 02, 2007 6:42 pm UTC
- Forum: Logic Puzzles
- Topic: Airplane On A Treadmill
- Replies:
**304** - Views:
**76160**

If the treadmill matches the speed of the wheels, in the sense that the treadmill goes backwards with the speed that the wheels would be spinning if the airplane was on solid ground, then Vtreadmill = Vwheels (...) And replacing it into hte 1st equation we get Vtreadmill = Vtreadmill + C which is i...

- Wed Feb 28, 2007 1:25 am UTC
- Forum: Logic Puzzles
- Topic: Donuts Revisited [solution discussion]
- Replies:
**10** - Views:
**3810**

- Sat Feb 24, 2007 9:03 pm UTC
- Forum: Logic Puzzles
- Topic: LSK's arbitrary logic puzzle, round 2 (Thread has SOLUTIONS)
- Replies:
**7** - Views:
**4563**

Statement 1 is not subject to true/false semantics. Statement 2 is a tautology. Finally, statement 3 is incomprehensible. Now, we know there are two types of robots. The basic ones that tell the truth, and the corrupted ones that may lie to advance their cause (destroying all humans), but otherwise ...

- Sat Feb 17, 2007 8:01 pm UTC
- Forum: Logic Puzzles
- Topic: You should be able to solve this!
- Replies:
**37** - Views:
**14244**

- Sat Jan 20, 2007 1:49 am UTC
- Forum: Logic Puzzles
- Topic: The Pirate Proof [Solution Thread]
- Replies:
**5** - Views:
**3532**

Didn't we already have this? It looks like http://forums.xkcd.com/viewtopic.php?t=330 with different constants. 1. x,x,x,x,1001 - Automatic pass 2. x,x,x,1001,0 - Automatic pass 3. x,x,1000,0,1 - 5th gets less in the next case, so he supports it. Passes 2 vs 1. 4. x,1000,0,1,0 - 4th gets less in the...

- Thu Jan 04, 2007 7:33 pm UTC
- Forum: Forum Games
- Topic: 3 letters in a word
- Replies:
**1795** - Views:
**250545**

- Thu Jan 04, 2007 1:56 pm UTC
- Forum: Forum Games
- Topic: 3 letters in a word
- Replies:
**1795** - Views:
**250545**

- Thu Jan 04, 2007 1:40 pm UTC
- Forum: Logic Puzzles
- Topic: #12: Remember Eeyore's Shack?
- Replies:
**6** - Views:
**3665**

I suspect this is http://forums.xkcd.com/viewtopic.php?t=732

- Fri Dec 22, 2006 10:23 pm UTC
- Forum: Logic Puzzles
- Topic: Attacking queens
- Replies:
**7** - Views:
**3419**

- Thu Dec 21, 2006 11:02 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0197: "Ninja Turtles"
- Replies:
**54** - Views:
**24265**

- Wed Dec 20, 2006 12:30 pm UTC
- Forum: Logic Puzzles
- Topic: The Narcoleptic Bookworm: Solution Thread
- Replies:
**14** - Views:
**5033**

- Sat Dec 16, 2006 3:08 pm UTC
- Forum: Logic Puzzles
- Topic: The Man Who Shot Liberty Valance - [solutions]
- Replies:
**15** - Views:
**5624**

Two main ways to obtain 4 in a container, by adding together two or by subtracting from one. Addition implies we already have 4 in the third container, so it is of no use. For subtraction, we have options 5-1, 6-2, 7-3, 8-4. 5-1 must pour into a 2/3 6-2 must pour into a 1/3 7-3 must pour into a 0/3 ...

- Sat Dec 16, 2006 1:10 pm UTC
- Forum: Logic Puzzles
- Topic: The Man Who Shot Liberty Valance - [solutions]
- Replies:
**15** - Views:
**5624**

null - possible Since BC is possible, null is possible. A - possible 0 8 - 0 5 3 - 0 3 - 5 0 3 - 2 3 3 3 - 2 6 0 - 2 6 - 0 2 6 - 2 0 6 0 - 2 1 5 - 2 1 - 5 2 1 - 4 3 1 3 - 4 B - possible Since BC is possible, B is possible. C - possible Since BC is possible, C is possible. AB - impossible At some po...

- Sat Dec 16, 2006 12:45 pm UTC
- Forum: Logic Puzzles
- Topic: Choose a donut [solutions]
- Replies:
**4** - Views:
**3015**

We can reduce the problem by limiting the population of co-workers to two, and then checking the possible combinations. More than two has no effect, as there are at most two donuts to be eaten. Less than two results in there always being donuts remaining. If both have a preference, you should take f...

- Thu Dec 14, 2006 12:15 pm UTC
- Forum: Logic Puzzles
- Topic: Seats on ANOTHER plane! [Solution Thread]
- Replies:
**8** - Views:
**3311**

Ah, I notice what I missed. If several people are sitting in the first seat, that should skew the distribution on p(n-1) towards success, since lots of people are sitting in the first seat there. Cosmologicon's hypothesis looks good: p(2) = 3/4 = 3^1 / 2^2 p(3) = 16/27 = 4^2 / 3^3 p(4) = 125/256 = 5...

- Thu Dec 14, 2006 12:02 am UTC
- Forum: Logic Puzzles
- Topic: Seats on ANOTHER plane! [Solution Thread]
- Replies:
**8** - Views:
**3311**

I arrived at the same result as Token posted in the problem thread: If there are more than x reservations among the x last seats, the seating fails. I also arrived at the same conclusion that the combinatorics were way too much work. :) Actually... Let p(n) be the chance of seating working out for n...

- Wed Dec 13, 2006 5:50 pm UTC
- Forum: Logic Puzzles
- Topic: Seats on a plane!
- Replies:
**13** - Views:
**4912**

I did the same induction proof that's already been done several times, but I don't feel like just discarding all the text I wrote. :) We observe that the following two situations are identical: * A is going to sit down first, so he chooses randomly * A is going to sit down, but someone else has take...

- Mon Dec 11, 2006 12:50 pm UTC
- Forum: Logic Puzzles
- Topic: Lightbulbs in a circle [solution]
- Replies:
**5** - Views:
**3201**

### Lightbulbs in a circle [solution]

http://forums.xkcd.com/viewtopic.php?t=914 There are n lightbulbs in a circle. Each lightbulb can be either on or off. When a button is pushed, the lightbulbs will change as follows, once every second: if a lightbulb is in the same state (both off or both on) as its clockwise neighbor, it will be tu...

- Sun Dec 10, 2006 12:56 am UTC
- Forum: Logic Puzzles
- Topic: Envelopes puzzle
- Replies:
**10** - Views:
**5824**

I thought we had done this one... There is x in envelope A. There is either 2x or x/2 in envelope B, giving expected value 1.25x. So we switch to B. We know there's either 2x or x/2 in envelope B and x in A. Let us call the value of B y. The expected value of A is then y/2 (A:x, B:2x) or 2y (A:x, B:...

- Fri Dec 08, 2006 7:47 am UTC
- Forum: Logic Puzzles
- Topic: The Vector Guessing Game [spoilers]
- Replies:
**10** - Views:
**4048**

- Wed Dec 06, 2006 4:13 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0193: "The Perfect Sound"
- Replies:
**47** - Views:
**17553**

- Wed Dec 06, 2006 2:33 am UTC
- Forum: Logic Puzzles
- Topic: A Monkey and a Typewriter
- Replies:
**66** - Views:
**23022**

You're using strings of different length. There should be an x option for abcdef as well in the first case. Point of interest: Any case of restarting the sequence completely is irrelevant to the question. Both sequences can restart at any point, and if one sequence is more likely after restarting th...

- Sun Dec 03, 2006 11:48 pm UTC
- Forum: Logic Puzzles
- Topic: Unfair beans
- Replies:
**7** - Views:
**3632**

- Sun Dec 03, 2006 11:21 am UTC
- Forum: Logic Puzzles
- Topic: 3 Spiders and a Fly [solution thread]
- Replies:
**15** - Views:
**6217**

- Sat Dec 02, 2006 11:43 am UTC
- Forum: Logic Puzzles
- Topic: Snakes on a Plane solution thread (spoilers)
- Replies:
**29** - Views:
**8653**

- Sat Dec 02, 2006 11:37 am UTC
- Forum: Logic Puzzles
- Topic: Temperatures
- Replies:
**60** - Views:
**13058**

I'd like to say that ostriches aren't birds. I really would. However, flight is not a defining characteristic: feathers, external reproduction... and... um... well, those two are. With the numerical scales, having infinity, 0, and -infinity are defining/required characteristics. So the natural numb...

- Fri Dec 01, 2006 5:13 pm UTC
- Forum: Logic Puzzles
- Topic: Snakes on a Plane solution thread (spoilers)
- Replies:
**29** - Views:
**8653**

Close, but your comma snake is not touched by a snout. Maybe he's afraid they'll bite him! Who are you to judge the poor snake and his irrational fears? Second run: Without loss of generality, we can assume snake A touches snake B head-middle, snake C middle-tail and snake D tail-head. Snake B's ta...

- Fri Dec 01, 2006 4:00 pm UTC
- Forum: Logic Puzzles
- Topic: Things that don't amount to short enough titles [SOLUTION]
- Replies:
**25** - Views:
**9395**

The problem thread is Things that don't amount to more than a hill of beans, a title which is too long for attaching [solution].

- Fri Dec 01, 2006 9:55 am UTC
- Forum: Logic Puzzles
- Topic: Snakes on a Plane solution thread (spoilers)
- Replies:
**29** - Views:
**8653**

- Thu Nov 30, 2006 12:03 am UTC
- Forum: Logic Puzzles
- Topic: A Very Large Graph
- Replies:
**14** - Views:
**5610**

You talk about what happens in the limit, but the limits seem to show the opposite. Suppose you add 3 vertices the first turn and 2 the following turns. The number of vertices minus one is then 2n. The number of edges is n. If the graph is connected, the ratio edges / (vertices minus one) must be gr...

- Wed Nov 29, 2006 9:40 pm UTC
- Forum: Logic Puzzles
- Topic: A Very Large Graph
- Replies:
**14** - Views:
**5610**

This seems exceedingly trivial, so there's probably a missing detail. #1 draws 3 vertices the first turn, then 1 vertex every other turn. After n turns, he will have drawn n+2 vertices. #2 will have drawn n edges, but n+1 edges are required to connect the graph. 3 and 1 are both finite numbers, and ...