## Search found 855 matches

Thu Aug 20, 2009 2:40 am UTC
Forum: Logic Puzzles
Topic: bridges of konigsberg
Replies: 5
Views: 1632

### Re: bridges of konigsberg

This changes nothing. Suppose you could solve the bridges of Königsberg using these augmented conditions. Now on the original map, replace each bridge i with a i copies, where a i is the number of times that bridge was used in your augmented solution. So now there's a normal solution on this aug...
Tue Aug 18, 2009 3:47 pm UTC
Forum: Logic Puzzles
Topic: bridges of konigsberg
Replies: 5
Views: 1632

### Re: bridges of konigsberg

It's true that, for someone who already understands the problem, you won't be able to find a solvable graph that will take 7-8 minutes, unless it's a graph so unwieldy that it actually takes that long to find out which vertices have even and odd degree. But your question isn't unreasonable. It's one...
Wed Jul 29, 2009 5:47 pm UTC
Forum: Logic Puzzles
Topic: Highest percentage of words from a set of letters?
Replies: 17
Views: 2752

### Re: Highest percentage of words from a set of letters?

Wed Jul 29, 2009 4:56 pm UTC
Forum: Logic Puzzles
Topic: Highest percentage of words from a set of letters?
Replies: 17
Views: 2752

### Re: Highest percentage of words from a set of letters?

We might need some clarification on what constitutes an English word. Pick a Scrabble dictionary, say? If we're just confining ourselves to any old dictionary, then WWW has a pretty good percentage for three letters. I think I can prove it's optimal. SS: OPST has six: opts, post, pots, spot, stop, t...
Wed Jul 29, 2009 1:33 pm UTC
Forum: Logic Puzzles
Topic: Alphabet
Replies: 15
Views: 2267

### Re: Alphabet

Also,

1. ABEHIKMNOPTXYZ
2. CDFGJLQRSUVW

F was in the first set for a while, before changing sides.
Sun Jul 26, 2009 9:30 pm UTC
Forum: Logic Puzzles
Topic: Alphabet
Replies: 15
Views: 2267

### Re: Alphabet

skeptical scientist wrote:What property have I used to make this division?

Spoiler:
Subgroups of D4

EDIT: Also, I remembered what #7 was. Meh.
Sun Jul 26, 2009 9:12 pm UTC
Forum: Logic Puzzles
Topic: Alphabet
Replies: 15
Views: 2267

### Re: Alphabet

On a related note, I can't for the life of me remember what the answer to #7 in the linked thread was:
I wrote:7: EGMPTYZ
Any ideas?
Sun Jul 26, 2009 8:38 pm UTC
Forum: Logic Puzzles
Topic: Alphabet
Replies: 15
Views: 2267

### Re: Alphabet

A bunch more of these here. Ended's might be #22, since knowing the answer to that one I can see why Q might be controversial.
Sat Jul 25, 2009 6:25 pm UTC
Forum: Mathematics
Topic: Introductions.
Replies: 8
Views: 1277

### Re: Introductions.

"English."
"Oh, I've always been illiterate."
Wed Jul 22, 2009 12:48 am UTC
Forum: Logic Puzzles
Topic: A Question of Art
Replies: 30
Views: 6169

### Re: A Question of Art

Spoiler:
The first part seems to be cluing "Marquis", but I couldn't get anywhere past that (unless the answer is Saskatchewan). Going off EnderSword's idea, there's this, but I kinda doubt the relevance.
Wed Jul 22, 2009 12:39 am UTC
Forum: Mathematics
Topic: 1=2?
Replies: 9
Views: 1261

### Re: 1=2?

Kurushimi wrote:Uh, that didn't even prove i^2 = 1; it proved i = 1/i.

I'm sure you can fill in the gaps to show the latter implies the former.
Mon Jul 20, 2009 12:50 am UTC
Forum: Logic Puzzles
Topic: tax
Replies: 11
Views: 1688

### Re: tax

Yes and no. It's true that I rarely stop playing a decent game because of sexism (Lufia II being the only counterexample I can think of). But I don't think it's unreasonable to hold MMOs to a higher standard, for a number of reasons. One is because you actually care about who you're interacting with...
Mon Jul 20, 2009 12:20 am UTC
Forum: Logic Puzzles
Topic: tax
Replies: 11
Views: 1688

### Re: tax

thc wrote:You could say the same thing about every game.

I often do.

And while I agree that it's tacky, I don't see how you can possibly not see it as sexist too. But that's a discussion for another forum, I guess.
Sat Jul 18, 2009 5:45 pm UTC
Forum: Logic Puzzles
Topic: tax
Replies: 11
Views: 1688

### Re: tax

shadyraptors wrote:... what's wrong with it?

Well, it's totally sexist. But at least it inspired you to discover the Laffer curve, right?
Thu Jul 16, 2009 12:48 am UTC
Forum: Logic Puzzles
Topic: "A legal poser"
Replies: 4
Views: 1533

### Re: "A legal poser"

Murder, of course. And the sloth-owner was charged with a traffic offense. I'm guessing based on the source that the lawyer's puzzle wasn't meant to be solvable, so I was pleasantly surprised to find out that there is actually a solution. EDIT: Wait, no, I made a faulty assumption. There are a coup...
Tue Jul 14, 2009 11:10 am UTC
Forum: Logic Puzzles
Topic: a riddle
Replies: 20
Views: 7388

### Re: a riddle

Ah.
Spoiler:
So one was twenty and the other was twenty too.
Tue Jul 14, 2009 1:23 am UTC
Forum: Logic Puzzles
Replies: 12
Views: 1973

### Re: Describe your starting point.

Clearly the 1km east must correspond to a full circuit of the pole. So, without actually doing the math, we had to start at a point 1km north of the line of latitude around the South Pole with circumference 1km. (And of course, if we hadn't need be "near" the South Pole, starting ...
Tue Jul 14, 2009 12:42 am UTC
Forum: Logic Puzzles
Topic: a riddle
Replies: 20
Views: 7388

### Re: a riddle

quintopia wrote:I thought of the whole "place called March or April" thing too, but I cannot find a single such city.

Here's one.
Mon Jul 13, 2009 8:31 pm UTC
Forum: Logic Puzzles
Topic: a riddle
Replies: 20
Views: 7388

### Re: a riddle

true. I don't actually chop off hands. I'm just slightly frustrated that the simplest explanations were rejected. That's a little confident, isn't it? Have you proven that there are no simpler explanations? They were born in a place called March, sometime in the month of April. Or they were born in...
Thu Jul 09, 2009 8:15 pm UTC
Forum: Mathematics
Topic: math book club
Replies: 62
Views: 4359

### Re: math book club

So you'd basically pick a topic everyone is interested in, pick a book, and get everyone together say, once every two weeks to make sure everyone understood? Isn't that one called "grad school"? This is what reading courses are. Except it's more often a collection of papers on a particula...
Thu Jul 09, 2009 4:06 pm UTC
Forum: Mathematics
Topic: What should I learn.
Replies: 47
Views: 4065

### Re: What should I learn.

...and annoy my math teachers with complex concepts that I understand. Don't do this. It's why people hate us. Seriously, yes, it sucks that most high school math instructors in this country don't know what real mathematics is about. But that's the system's fault. Please don't take it out on the te...
Thu Jul 09, 2009 4:03 pm UTC
Forum: Mathematics
Topic: Math Riddle
Replies: 46
Views: 5013

### Re: Math Riddle

You two are being really silly. I'm normally in full support of meaningless semantic discussions with a paucity of math content, but this one left the realm of being interesting several days ago.
Wed Jul 08, 2009 8:35 pm UTC
Forum: Mathematics
Topic: From recursive to explicit?
Replies: 19
Views: 3119

### Re: From recursive to explicit?

Random832 wrote:What if you have really small handwriting?

Eh, I thought it was a reasonable assumption that each digit would use at least one atom of ink.
Wed Jul 08, 2009 4:53 pm UTC
Forum: Mathematics
Topic: From recursive to explicit?
Replies: 19
Views: 3119

### Re: From recursive to explicit?

In fact, just writing the fifth term out would require more atoms of ink than there are atoms in the universe. Likewise, of course, with writing the sixth term as three to some power.
Tue Jul 07, 2009 2:45 pm UTC
Forum: Mathematics
Topic: Egyptian fractions
Replies: 13
Views: 2505

### Re: Egyptian fractions

For the same reason you can get 11, you can always get twice a perfect number minus 1. For instance, 28 is perfect, and 2+4+7+14+28=55, and 1/2+1/4+1/7+1/14+1/28=1. Oh, and you can also get numbers of the form n(n+1) 2 . This is because \frac1n-\frac1{n+1}=\frac1{n(n+1)} \Longrightarrow n\fr...
Sun Jun 28, 2009 8:44 pm UTC
Forum: Logic Puzzles
Topic: Is English trivial?
Replies: 21
Views: 3078

### Re: Is English trivial?

skeptical scientist wrote:Here's a list of letters that commute with a.

Here's one more:
Spoiler:
hose=hoes => se=es; gas=sag; ages=sage=gase=gaes => ag=ga.
Sun Jun 28, 2009 3:30 pm UTC
Forum: Logic Puzzles
Topic: Is English trivial?
Replies: 21
Views: 3078

### Re: Is English trivial?

When I proposed this problem to a friend yesterday, he referred me to #5 here . (For those who can't access JSTOR, the problem is to find the center of G modulo the relation that for any English anagrams xyzzy and zyxyz, xyzzy~zyxyz. So for instance ab=ba, since able=bale.) I'm tempted to have a go ...
Sat Jun 27, 2009 9:27 pm UTC
Forum: Mathematics
Topic: What should I learn.
Replies: 47
Views: 4065

### Re: What should I learn.

Why would anyone use Lang except under coercion? If this is just for fun, choose a pleasant little text like Gallian.
Sat Jun 27, 2009 6:50 pm UTC
Forum: Logic Puzzles
Topic: Is English trivial?
Replies: 21
Views: 3078

### Re: Is English trivial?

Building off of the above two posts: We also have sail=tack (more or less), so sail=nail, thus s=n="". Can we knock more letters down? It would be especially convenient if we had e equal to the identity as well. EDIT: Some more. Also, inflammable=flammable, so i=in="" as ...
Sat Jun 27, 2009 4:34 pm UTC
Forum: Mathematics
Topic: What should I learn.
Replies: 47
Views: 4065

### Re: What should I learn.

Hungarian recommendation time! Consider reading Proofs and Refutations by Imre Lakatos (who seems to share your surname) and Conjecture and Proof by Miklós Laczkovich. The first is, I think, a good demonstration of what higher-level mathematical thinking can look like. The latter is a fantastic tour...
Fri Jun 26, 2009 8:56 pm UTC
Forum: Mathematics
Topic: Figuring out # of possible paths?
Replies: 6
Views: 973

### Re: Figuring out # of possible paths?

merfed wrote:At this state, the '''Change Y axis''' rule overrides the '''No Diagonal moves''' rule.

What does this mean? When is one allowed to "override" certain rules?
Fri Jun 26, 2009 4:20 pm UTC
Forum: Mathematics
Topic: Math Riddle
Replies: 46
Views: 5013

Its normal to always have something on altering the temp? Really? Because I go more than six months of the year with no such object. And seriously, $300 a month? When I have to pay that for 3 months I'm pissed off. Or is this for a family or something? I dunno, I was trying to shoot for as big a nu... Fri Jun 26, 2009 1:48 pm UTC Forum: Mathematics Topic: Math Riddle Replies: 46 Views: 5013 ### Re: Math Riddle And if Kevin's electricity consumption were remotely normal (let's be generous and say$300/month, which is what you might expect using space heaters or air conditioning at all times), then it'll take more than a century for the solar panels to pay for themselves anyway.
Thu Jun 25, 2009 10:32 pm UTC
Forum: Mathematics
Topic: Math Riddle
Replies: 46
Views: 5013

### Re: Math Riddle

Since Kevin is using approximately five thousand times as much electricity as the average person (read: me), I imagine the Feds will figure out what that power is for and bust him before the solar panels can pay for themselves.
Wed Jun 17, 2009 2:03 pm UTC
Forum: Mathematics
Topic: I've got a question:
Replies: 9
Views: 1103

### Re: I've got a question:

skeptical scientist wrote:This is because a map of the world is not exactly a contraction.

The biggest problem, of course, is that it's not continuous.
Tue Jun 16, 2009 7:24 pm UTC
Forum: Mathematics
Topic: I've got a question:
Replies: 9
Views: 1103

### Re: I've got a question:

* this may break down if you're standing somewhere (e.g. north pole) which is at the edge of your map, or if the map has repeated regions. I think in these cases you will get at least one point. You can get zero in certain situations. For instance, take a Mercator projection map that has the Americ...
Sun Jun 07, 2009 10:54 pm UTC
Forum: Mathematics
Topic: What's a good Probability Theory textbook?
Replies: 5
Views: 1209

### Re: What's a good Probability Theory textbook?

I haven't read it myself, but I know people who swear by Feller.
Sat Jun 06, 2009 3:59 pm UTC
Forum: Mathematics
Topic: Choose balls, odds same color?
Replies: 6
Views: 1210

### Re: Choose balls, odds same color?

Yes, good. Now a followup question. Can someone find an elegant combinatorial proof that it's 1/2, which involves no computation? Specifically, I mean an involution f on the set of the 36 possible marble choices such that {x,y} are the same color if and only if f({x,y}) aren't? I can't think of a ni...
Sat Jun 06, 2009 2:47 am UTC
Forum: Mathematics
Topic: Choose balls, odds same color?
Replies: 6
Views: 1210

### Re: Choose balls, odds same color?

I'm not sure I get why you multiply terms by 3/9 or 6/9 in the numerator.
Fri Jun 05, 2009 12:41 am UTC
Forum: Mathematics
Topic: Hitting Walls in Proofs
Replies: 15
Views: 1591

### Re: Hitting Walls in Proofs

I once had a professor who measured how long we should work on a problem set by the number of showers we should take. I also endorse train rides.