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Tricky Questions!!!

 
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Jan19-07, 04:03 PM   #52
 

Tricky Questions!!!


Quote by DaveC426913 View Post
Quote by powergirl
Exactly how many slices of 1.5 cm each can you cut from a whole bread which is 22.5 cm long?
Everybody knows that 4 cuts divide something into 5 slices.

So 16.
I don't get it... She's asking how many slices, right? And each slice has to be exactly 1.5 cm long? And the whole bread loaf is 22.5 cm long? And 22.5/1.5 = 15, so 15 slices, right? Which means 14 cuts? And that's assuming each cut is perfect and infintesimally thin. Am I missing some hidden caveat of the problem? Does an end piece not count as a slice or something?

DaveE
Jan19-07, 04:05 PM   #53
 
Quote by davee123 View Post
I don't get it...

DaveE
That's because I am wrong and you are right.
Jan20-07, 04:59 AM   #54
 
Quote by davee123 View Post
I don't get it... She's asking how many slices, right? And each slice has to be exactly 1.5 cm long? And the whole bread loaf is 22.5 cm long? And 22.5/1.5 = 15, so 15 slices, right? Which means 14 cuts? And that's assuming each cut is perfect and infintesimally thin. Am I missing some hidden caveat of the problem? Does an end piece not count as a slice or something?

DaveE
I think that U must approach this Question in a tricky way...
ANSWER is not right anyway....
Am waiting for someone to think of this question once more..and gimme a tricky ans:
Jan20-07, 05:14 AM   #55
 
Quote by powergirl View Post
A landlord is threatening to evict a father and his beautiful young daughter, unless she agrees to marry him. In a false gesture of sincerity, he offers her an opportunity for her and her father to remain in the house, without marrying him. He has a silk bag in which he says he has placed a white and a black stone from the footpath on which they're standing. If she picks the white stone from the bag, without looking, she wins; if she picks the black, she loses. However, the young girl saw him place two black stones in the bag. She can't expose him in front of the witnesses without angering him and making things worse. How does the clever girl win?
The stones in the bag problem is a derivative of a black and white grape, the person in question quickly pulls out and eats one of the grapes, saying look in the bag, and lo and behold the grape in the bag is black so his must of been white.

A man is told that he is to be sentenced. The judge asks if he has anything to say and the man says, if I can plunge my hands into boiling water and keep them there for a few minutes would this not show that the Gods favoured me, and that I was innocent?

Interested by the mans show of piety the judge acceeds. How does the man plunge his hands into boiling water for a few minutes without sustaining injury? Assume that he has no protective measures on his hands, such as gloves,any sort of barrier.
Jan20-07, 06:17 AM   #56
 
Am waiting for someone to think of this question once more..and gimme a tricky ans:
Well no one said the slices must be of the same volume, so I would think of slicing perpendicularly to the longest diagonal. Of course we haven't been given the other two dimensions for the bread. With a perfectly sharp knife, no substance would be lost through cutting.
Jan20-07, 09:11 AM   #57
 
Quote by powergirl View Post
I think that U must approach this Question in a tricky way...
ANSWER is not right anyway....
Am waiting for someone to think of this question once more..and gimme a tricky ans:
"tricky" answer...

Well, 14 cuts will give you 15 slices of bread, each 1.5cm in thickness. If there is more to this puzzle, I'm afraid you haven't communicated it.
Jan20-07, 09:13 AM   #58
 
Quote by Schrodinger's Dog View Post
A man is told that he is to be sentenced. The judge asks if he has anything to say and the man says, if I can plunge my hands into boiling water and keep them there for a few minutes would this not show that the Gods favoured me, and that I was innocent?

Interested by the mans show of piety the judge acceeds. How does the man plunge his hands into boiling water for a few minutes without sustaining injury? Assume that he has no protective measures on his hands, such as gloves,any sort of barrier.
They are on the peak of Mount Everest? In space? Um...
Jan21-07, 12:37 AM   #59
 
Quote by Schrodinger's Dog View Post
How does the man plunge his hands into boiling water for a few minutes without sustaining injury?
Hm. Possibilities:

1) The water is boiling, but at a lower temperature (as suggested, maybe at extremely high altitudes or in space or something)

2) The water does not sustain its boil

3) The amount of water is insignificantly small

4) He somehow is able to avoid contact with the water

5) His hands are artificial and unaffected by boiling water (or perhaps are already damaged sufficiently so that they aren't negatively affected)

6) "His" hands are not the hands which are attached to his physical body

I think I like number 5 best, though...

DaveE
Jan21-07, 12:25 PM   #60
 
How does the man plunge his hands into boiling water for a few minutes without sustaining injury?
I suspect the answer is more elegant than any of DaveE's - it'll be of "the truck with its lights off" variety. The answer is based on information we already know, the trick is the assumptions we apply.

I was wondering if it were something like "the water 'boiling' off the surface of regular luke warm water into the air" but that's not boiling at all.




Schrodinger: I notice that the puzzle itself doesn't say anything about him not being injured, though the question asks how he can not sustain injury. Can we safely say that "he holds his hands in the boiling water through sheer willpower and they come out horribly scalded" is not the answer we're looking for?
Jan21-07, 12:59 PM   #61
 
Quote by DaveC426913 View Post
I suspect the answer is more elegant than any of DaveE's - it'll be of "the truck with its lights off" variety. The answer is based on information we already know, the trick is the assumptions we apply.
That's what I was kinda looking for-- what assumptions do we make? The question almost explicitly says that he submerges his hands fully into water which is boiling, and keeps them there, in water which remains boiling, for several minutes, such that his hands are in direct contact with the boiling water for the entire duration.

So, either the boiling isn't as bad as we assume it is, and any of us could do the same trick, OR he's special in some way and won't be affected. If it's the former, the only things I can think of are that the water isn't as hot as expected, there isn't as much of it as expected, or the water DOES stop boiling. If it's the latter, then there's some sort of trick with "his hands", which are somehow impervious to boiling water, or won't do "him" any injury.

So, I like the idea that he's got prosthetic hands, as suggested earlier. It's not too "out there", and covers an assumption that we'd probably make (and assumably the judge made too)

DaveE
Jan21-07, 02:49 PM   #62
 
Quote by davee123 View Post
So, I like the idea that he's got prosthetic hands, as suggested earlier. It's not too "out there", and covers an assumption that we'd probably make (and assumably the judge made too)

DaveE
I think that would be a cheating answer. Artifical hands would be a critical clue that we were not given. I think we can safely "assume" his hands are really his hands.

I think it has to do with our assumptions about the boiling water.
Jan29-07, 12:44 AM   #63
 
Quote by DaveC426913 View Post
They are on the peak of Mount Everest? In space? Um...
Quote by davee123 View Post
Hm. Possibilities:

1) The water is boiling, but at a lower temperature (as suggested, maybe at extremely high altitudes or in space or something)

2) The water does not sustain its boil

3) The amount of water is insignificantly small

4) He somehow is able to avoid contact with the water

5) His hands are artificial and unaffected by boiling water (or perhaps are already damaged sufficiently so that they aren't negatively affected)

6) "His" hands are not the hands which are attached to his physical body

I think I like number 5 best, though...

DaveE

Both right, the man lives in India and asks if he might be tried before the Gods themselves at the top of a very high mountain peak where a small Budhist shrine sits, the judge impressed once again by his piety acceeds. Of course at the top of the mountain the boiling point of water is much lower and so this and the resultant cold mean the man picks up a couple of handfulls of snow and plunges his hands into the water; he escapes with rather red hands and in some pain but no permanent damage, the man is freed, blessed as he is by the Gods themselves

I figured this'd be an easy one on a physics forum

So yes, altitude matters for boiling. At sea level, water boils at
approximately 100 degrees Celsius. In the Denver area where I live, the
atmospheric pressure is about 83% of that at sea level, and water boils at
about 95 degrees C. Atop Mount Everest, it is about 34% of sea level,
which translates into boiling at about 72 degrees C.
Quote by Schrodinger's Dog View Post
The stones in the bag problem is a derivative of a black and white grape, the person in question quickly pulls out and eats one of the grapes, saying look in the bag, and lo and behold the grape in the bag is black so his must of been white.

A man is told that he is to be sentenced. The judge asks if he has anything to say and the man says, if I can plunge my hands into boiling water and keep them there for a few minutes would this not show that the Gods favoured me, and that I was innocent?

Interested by the mans show of piety the judge acceeds. How does the man plunge his hands into boiling water for a few minutes without sustaining injury? Assume that he has no protective measures on his hands, such as gloves,any sort of barrier.
He's not allowed to wear gloves or a barrier, but carrying snow is not against the rules.

Incidently I think it was Aristotle who first posed the grape problem to one of his students? The student was Alexander the Great. He got it right too.
Jan29-07, 10:52 AM   #64
 
Quote by Schrodinger's Dog View Post
the man picks up a couple of handfulls of snow and plunges his hands into the water; he escapes with rather red hands and in some pain but no permanent damage, the man is freed, blessed as he is by the Gods themselves

I figured this'd be an easy one on a physics forum
Hmm, in looking further at this, I'm not sure this is actually possible. Looking on the Wikipedia: http://en.wikipedia.org/wiki/Burn_(injury)

Temperature/Duration until injury:
155F (68.3C) 1 second
145F (62.9C) 3 seconds
135F (57.2C) 10 seconds
130F (54.4C) 30 seconds
125F (51.6C) 2 minutes
120F (48.8C) 5 minutes

Guess it depends on how much snow he puts in, how quickly the cold water dissipates, and how long until the new water starts boiling (assuming that it's still being heated to keep the boil)!

DaveE
Jan29-07, 04:06 PM   #65
 
Quote by davee123 View Post
Hmm, in looking further at this, I'm not sure this is actually possible. Looking on the Wikipedia: http://en.wikipedia.org/wiki/Burn_(injury)

Temperature/Duration until injury:
155F (68.3C) 1 second
145F (62.9C) 3 seconds
135F (57.2C) 10 seconds
130F (54.4C) 30 seconds
125F (51.6C) 2 minutes
120F (48.8C) 5 minutes

Guess it depends on how much snow he puts in, how quickly the cold water dissipates, and how long until the new water starts boiling (assuming that it's still being heated to keep the boil)!

DaveE
I suppose you could take the holding a snowball even further. The problem states that he plunges his hands into boiling water, but it does not say that the water must remain boiling. If he held a 1L snowball in a pot containing 1L of boiling water, then the water temp would rapidly equalize at a very tolerable temp. You'd still want to do it on top of Everest, since that drops the boiling temp enough to forestall the worst of the initial damage.
Jan29-07, 04:07 PM   #66
 
So, since I got it right, I get to ask the next one?

as per post 51:

There exist simple English language sentences composed of only common words that can be correctly spoken but cannot be correctly written down. Provide an example (which will be incorrectly written of course).
Jan29-07, 04:27 PM   #67
 
Quote by DaveC426913 View Post
There exist simple English language sentences composed of only common words that can be correctly spoken but cannot be correctly written down. Provide an example (which will be incorrectly written of course).
I saw this before and I'm not sure I quite follow-- are you saying that it's incorrect grammattically, and hence can't be written down correctly, but is correct when spoken, thanks to something like homophones? I guess I'm not clear on how it could be incorrect when written, unless we're talking about either something that can't be pronounced with the constraints of the Roman character set, or something that's incorrect grammatically which happens to magically be incorrectly interpreted as a correct phrase when spoken. Otherwise, I'm not sure I understand how it's possible?

DaveE
Jan29-07, 04:37 PM   #68
 
Quote by davee123 View Post
Hmm, in looking further at this, I'm not sure this is actually possible. Looking on the Wikipedia: http://en.wikipedia.org/wiki/Burn_(injury)

Temperature/Duration until injury:
155F (68.3C) 1 second
145F (62.9C) 3 seconds
135F (57.2C) 10 seconds
130F (54.4C) 30 seconds
125F (51.6C) 2 minutes
120F (48.8C) 5 minutes

Guess it depends on how much snow he puts in, how quickly the cold water dissipates, and how long until the new water starts boiling (assuming that it's still being heated to keep the boil)!

DaveE
You seem to forget that at that altitude and coldness the water will cool very quickly, assuming he has his hands in the snow for enough time for it to cool and his hands start off at say something close to 10 degrees C(50F) He could get away with it, and note I didn't say without x, just able to do it. Only way to answer this is to do it though but in theory it should be possible.

And question is answered.

Quote by DaveC426913 View Post
I suppose you could take the holding a snowball even further. The problem states that he plunges his hands into boiling water, but it does not say that the water must remain boiling. If he held a 1L snowball in a pot containing 1L of boiling water, then the water temp would rapidly equalize at a very tolerable temp. You'd still want to do it on top of Everest, since that drops the boiling temp enough to forestall the worst of the initial damage.
Exactly don't forget the snow in his hands also. at something close to 0 or most probably much less.

Think of the cooling effect of holding snow at say -15F, now it melts into the liquid at 72c?
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