What Are Your Best Mind-Boggling Questions?

• dpa
In summary, Alice walks north, turns around and walks south, then turns around and walks west, and is back at her house after walking a total of 20 km.
dpa
hi all,
i want you to post best mind boggling/twisting questions you know of.
Thanks
dpa

Why is it that sometimes my pain pills work one day and not the next for the same symptom?

Will you be answering our questions?

By what stretch of the imagination is this "art"?

sorry but i was not expecting humour.
You know, the problem solving kinda.
And i am not going to answer on forum. We can think on our own.
Its so simple. The date of pills expired exactly after you took them the previous day. It's as simple as that.

A player kicks a ball and it comes back to him without bouncing off of anything else, how is this possible?

DragonPetter said:
A player kicks a ball and it comes back to him without bouncing off of anything else, how is this possible?
He kicks it up

Ryan_m_b said:
He kicks it up

No, he kicks it into a hurricane that blows it back at him.

One person's boggle line is different from another's. Most PFers would find this question pretty easy, I think:

Alice leaves her house and walks north for 5 km. Then she turns and walks west for 5 km. Then she turns south and walks 5 km, and is back at her house, where she started. How is this possible?

lisab said:
One person's boggle line is different from another's. Most PFers would find this question pretty easy, I think:

Alice leaves her house and walks north for 5 km. Then she turns and walks west for 5 km. Then she turns south and walks 5 km, and is back at her house, where she started. How is this possible?
Something to do with this?

lisab said:
One person's boggle line is different from another's. Most PFers would find this question pretty easy, I think:

Alice leaves her house and walks north for 5 km. Then she turns and walks west for 5 km. Then she turns south and walks 5 km, and is back at her house, where she started. How is this possible?
I bet Alice's toes are frozen.

~~~

Here's an oldie I really love: You're in a room with 2 doors and 2 guards. One of the doors leads to freedom, the other to death, you don't know which is which. One of the guards always tells the truth the always lies but you don't know which guard is which.

You are allowed to ask one of the guards one question to gain your freedom. What do you ask?

Lemme fix that for you
lisab said:
Alice leaves her bear friend and walks SOUTH for 5 km. Then she turns and walks west for 5 km. Then she turns NORTH and walks 5 km, and is back at her friend's, where she started.
What color is the bear's fur ?

Q_Goest said:
I bet Alice's toes are frozen.

~~~

Here's an oldie I really love: You're in a room with 2 doors and 2 guards. One of the doors leads to freedom, the other to death, you don't know which is which. One of the guards always tells the truth the always lies but you don't know which guard is which.

You are allowed to ask one of the guards one question to gain your freedom. What do you ask?

You ask one guard what the other guard would say if you asked him which door leads to freedom.

Think about the set of all sets that are not members of themselves!

humanino said:
Lemme fix that for you

nice

By what stretch of the imagination is this "art"?
well if eons later that is the only piece of digital work that survives and everything even our way of sleeping changes, then this would be one of the most valued art piece.

dpa said:
well if eons later that is the only piece of digital work that survives and everything even our way of sleeping changes, then this would be one of the most valued art piece.
Woule it be art or just a picture of a messy bedroom? I believe it would be considered the latter.

you see you consider a broken rustic chalice or ancient vase as work of art and preserve in a museum and even pay millions.

Yeah, its all about how you define art as!

dpa said:
you see you consider a broken rustic chalice or ancient vase as work of art and preserve in a museum and even pay millions.

Yeah, its all about how you define art as!
It's not so much art as an historical piece.

lisab said:
One person's boggle line is different from another's. Most PFers would find this question pretty easy, I think:

Alice leaves her house and walks north for 5 km. Then she turns and walks west for 5 km. Then she turns south and walks 5 km, and is back at her house, where she started. How is this possible?

I came up with two interesting solutions, and was working on a third at the bottom of this page that micromass might be interested in reading:

I'll post a link to the image so I don't spoil it:
http://i43.tinypic.com/ibawhs.jpg

QuarkCharmer said:
I came up with two interesting solutions, and was working on a third at the bottom of this page that micromass might be interested in reading:

I'll post a link to the image so I don't spoil it:
http://i43.tinypic.com/ibawhs.jpg

That made me lol! I love it!

Nice kitty

QuarkCharmer said:
I came up with two interesting solutions, and was working on a third at the bottom of this page that micromass might be interested in reading:

I'll post a link to the image so I don't spoil it:
http://i43.tinypic.com/ibawhs.jpg

You can turn around several times, so there are actually infinitely many solutions of your type (1)

Type (2) is new to me however, and pretty neat

humanino said:
You can turn around several times, so there are actually infinitely many solutions of your type (1)

Type (2) is new to me however, and pretty neat

That's why the "equator" is there. It's really just a line describing the domain of alice's house.A short "mind boggling" problem with a "not short" answer:
http://www.mathpages.com/home/kmath668/kmath668_files/image001.gif
Infinite grid of resistors with resistance R. Find the resistance between two adjacent nodes.

I tried it for a long time, refusing to look for a solution. I finally caved though :(

(If you want to try it yourself, all you need to know is that resistors in series add up to an equivalent resistance, and resistors in parallel are equivalent by: $\frac{1}{R_{eq}} = \frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}+...+\frac{1}{R_{n}}$ )

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If a chicken and a half can lay an egg and a half in a day and a half, then how long will it take for a cockroach to kick all the seeds out of a cucumber?

dpa said:
you see you consider a broken rustic chalice or ancient vase as work of art and preserve in a museum and even pay millions.

Yeah, its all about how you define art as!
Evo said:
It's not so much art as an historical piece.
Exactly Evo. The fact that something is a historical artefact does not automatically make it art. When I visit museums to see ancient tools it is not because I want to go and see something artistic. Even if I go to see ancient art that is far more due to historical curiosity than artistic. If someone now made a cave painting it wouldn't interest me, what interests me is the historical significance.

DragonPetter said:
A player kicks a ball and it comes back to him without bouncing off of anything else, how is this possible?
Divine intervention.

Ryan_m_b said:
By what stretch of the imagination is this "art"?

It is art that is about vision enlarging and the deepening of your awareness.

At first sight the artist seems to be saying to the viewer Look at This! Look at This!But if you accept its challenge to enlarge your vision and expand your sensibilities you will realize the artist is saying Look at me! Look at me!

No, even that is too crude and reductive. M'as tu vu?! M'as tu vu?! sounds, and therefore is, better.

epenguin said:
It is art that is about vision enlarging and the deepening of your awareness.

At first sight the artist seems to be saying to the viewer Look at This! Look at This!

But if you accept its challenge to enlarge your vision and expand your sensibilities you will realize the artist is saying Look at me! Look at me!

No, even that is too crude and reductive. M'as tu vu?! M'as tu vu?! sounds, and therefore is, better.

Actually the art here is to make people think it's art. So it is art.

Mind boggling?

Hello quark charmer,

Is its solution related with the one with infinite row with two lines kind.

Do post here. That left me thinking for a while!

Evo said:
Woule it be art or just a picture of a messy bedroom? I believe it would be considered the latter.

It's art, because it tells a story. The person isn't messy - she's ill. And the reason she's not present in the scene is because she has rushed to the bathroom in a hurry, seeing as how she didn't bother putting on her slippers, meaning she's probably suffering from dyssentry.

QuarkCharmer said:
That's why the "equator" is there. It's really just a line describing the domain of alice's house.

A short "mind boggling" problem with a "not short" answer:
http://www.mathpages.com/home/kmath668/kmath668_files/image001.gif
Infinite grid of resistors with resistance R. Find the resistance between two adjacent nodes.

I tried it for a long time, refusing to look for a solution. I finally caved though :(

(If you want to try it yourself, all you need to know is that resistors in series add up to an equivalent resistance, and resistors in parallel are equivalent by: $\frac{1}{R_{eq}} = \frac{1}{R_{1}}+\frac{1}{R_{2}}+\frac{1}{R_{3}}+...+\frac{1}{R_{n}}$ )

If you put this problem on a sign and hold it up in front of the building housing the Physics and Math department, how many professors will you kill off?

http://xkcd.com/356/

Or, alternatively, how many PF members will you kill off?

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Ryan_m_b said:
Exactly Evo. The fact that something is a historical artefact does not automatically make it art.

And something made by an artist isn't necessarily art.

It's about the emotive response, and I think that's what DPA may have been referring to in the comparison between ancient artifacts & art.

I'll take some ancient tools, smash 'em up and make some art out of it.

DPA's digital picture of "art" turned ancient artifact is equal but opposite.

lisab said:
Alice leaves her house and walks north for 5 km. Then she turns and walks west for 5 km. Then she turns south and walks 5 km, and is back at her house, where she started. How is this possible?

Ryan_m_b said:
Something to do with this?

Q_Goest said:
I bet Alice's toes are frozen.
It's obvious with all the hints. Clearly, Alice lives about 5(1+1/2nPi) miles south of the North Pole ;)

Edit: Looks like QC Roll'd me to it =(

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A cylindrical hole is drilled diametrically through a sphere. If the height of the cylindrical wall generated is L, what's the volume of the remaining material?

If a car is traveling at 80 miles per hour, how long will it take to go 80 miles?

Jimmy Snyder said:
If a car is traveling at 80 miles per hour, how long will it take to go 80 miles?
Teasing the blonde again?

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