I am a sucker for them. Logic puzzles, too.
Do they drive you nuts or do you like them?
If you have any good ones, please share.
I like giving them as much as getting them.
Do they drive you nuts or do you like them?
If you have any good ones, please share.
I like giving them as much as getting them.
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Yet another line to tell the interviewer...
Punk!
Okay, I have one.
You have two ropes of uneven size and thickness. These ropes will each burn for an hour from one end to the other. (However, due to the variance within the ropes, each section's burn rate will vary, and each rope is different as well.) You also have matches.
How do you measure out 45 minutes using only the ropes and matches?
NO CHEATING.
Punk!
Okay, I have one.
You have two ropes of uneven size and thickness. These ropes will each burn for an hour from one end to the other. (However, due to the variance within the ropes, each section's burn rate will vary, and each rope is different as well.) You also have matches.
How do you measure out 45 minutes using only the ropes and matches?
NO CHEATING.
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Make a semicircle with the lengths of rope, use the matches to measure out 180 degrees, then measure out 45 minutes between two degree marks.
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But they burn at uneven rates, even within the same rope.
You don't know what the rates are either. The first inch might take 50 minutes, and the entire rest of the rope take 10 minutes.
The only thing you know for sure is that the entire thing will burn in an hour.
You don't know what the rates are either. The first inch might take 50 minutes, and the entire rest of the rope take 10 minutes.
The only thing you know for sure is that the entire thing will burn in an hour.
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Okay, I'm still working on it. If I light one of the ropes at both ends, when it burns out I've got 30 minutes. That much is easy. It's the 15 minutes I'm having trouble with.
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If you light one end of the second rope while the first one is burning from both ends, the second rope will be halfway burned by the time the first one is completely burned, or in 30 minutes. If you then light the other end of the second rope, it will be completely burned in 15 minutes, for a total of 45 mintues.
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