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Brain Teasers 2
- Thread starter bucknast
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I wasn't asking so I can be prepared with the answers, nor was I looking for a list of technical brain teasers, which are readily available on the internet. I wanted to know if any experienced engineers had come across an interview question they thought was particularly interesting, challenging, or illustrated the idea of a brain teaser, that is, to assess one's logical reasoning skills in a notable way. I posted my question here because this is an engineering forum, not a computer science one like most of the brain teaser sites are geared towards, as this has been popular in tech for a while.
MikeHalloran
Mechanical
"
A particular critical part's drawing carries a high limit for the number and volume of detectable voids.
...
What would be the maximum number and volume of undetectable voids?
"
Mike Halloran
Pembroke Pines, FL, USA
A particular critical part's drawing carries a high limit for the number and volume of detectable voids.
...
What would be the maximum number and volume of undetectable voids?
"
Mike Halloran
Pembroke Pines, FL, USA
I got asked in a phone interview for a position at Edwards AFB how many cars are there in the USA or something like that.
If I hadn't wanted the job so much I probably would have hung up on them.
If I hadn't wanted the job so much I probably would have hung up on them.
Posting guidelines faq731-376 (probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484
What is Engineering anyway: faq1088-1484
We had a problem like that in high school: how many molecules of a drop of rain from the Jurassic wound up in my canteen today? It was fun; the same problem showed up in freshman physics and drove a few people crazy for a while.
TTFN
faq731-376
TTFN
faq731-376
saintbasil
Mechanical
- Aug 17, 2012
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My favorite twos:
-How do you make something smaller?
-How do you define engineering?
-How do you make something smaller?
-How do you define engineering?
GregLocock
Automotive
"-How do you make something smaller?
-How do you define engineering? "
Probably a great way of finding out how sarcastic I'm feeling that day, maybe not so good at finding out how I think.
I like hammers, for making things smaller, and engineering is knowing which bits you can knock off and the thing will still work.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
-How do you define engineering? "
Probably a great way of finding out how sarcastic I'm feeling that day, maybe not so good at finding out how I think.
I like hammers, for making things smaller, and engineering is knowing which bits you can knock off and the thing will still work.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376
patprimmer
New member
Greg
My first reaction was with an axe, then I thought about it being steel.
Mike
Total volume of undetected voids is easy by apparent vs real SG after you account for detected voids. Number well not so easy other than the total volume vs minimum detectable size as a minimum number. I guess "who cares" would not go down well.
Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
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My first reaction was with an axe, then I thought about it being steel.
Mike
Total volume of undetected voids is easy by apparent vs real SG after you account for detected voids. Number well not so easy other than the total volume vs minimum detectable size as a minimum number. I guess "who cares" would not go down well.
Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &
for site rules
MikeHalloran
Mechanical
"Who cares?" is a correct answer. The voids are not detectable by ANY means including SG and part failure.
Mike Halloran
Pembroke Pines, FL, USA
Mike Halloran
Pembroke Pines, FL, USA
Mint is right - they are really looking for you to showcase your reasoning ability to find a logical answer. While not a brain teaser, a likely interview question that I've encountered before is "What is your greatest weakness"? I answered it by saying, "I have a low tolerance for incompetence". Be prepared for that one, since it may come up.
Maui
Maui
TenPenny - I disagree. You can't really call something a "void" unless there is actually extra space there beyond the atomic spacing in a perfect crystalline structure.
I would think minimum void size would be on the order of one atom missing from the crystal lattice. You would also need a one-atom thickness between voids, so each void needs to be surrounded on all faces by atoms. Argue that those atoms are "shared" between voids, make an assumption about crystal structure, and a ratio of atoms to voids (perhaps 3:1). Take the volume of the part and atomic spacing, calculate maximum theoretical number of voids. Max volume would be 1/4 of part volume (adjust if you don't agree with my ratio.)
I would think minimum void size would be on the order of one atom missing from the crystal lattice. You would also need a one-atom thickness between voids, so each void needs to be surrounded on all faces by atoms. Argue that those atoms are "shared" between voids, make an assumption about crystal structure, and a ratio of atoms to voids (perhaps 3:1). Take the volume of the part and atomic spacing, calculate maximum theoretical number of voids. Max volume would be 1/4 of part volume (adjust if you don't agree with my ratio.)
Got asked this in an interview, almost crapped my pants:
There are three men sitting in a row looking forward, each man can only see in-front of them and cannot see what is on their heads.
A box has three red hats in it and two blue hats, these hats are put on the men at random.
The man in the back is asked if he knows what color hat he is wearing, from observation of the men in front of him, he says no.
The man in the middle is asked if he knows what color hat he is wearing, from observation of the man in front of him, he says no.
The man in the front is asked if he knows what color hat he is wearing, from inference, he says yes.
What color hat is he wearing and how does he know?
There are three men sitting in a row looking forward, each man can only see in-front of them and cannot see what is on their heads.
A box has three red hats in it and two blue hats, these hats are put on the men at random.
The man in the back is asked if he knows what color hat he is wearing, from observation of the men in front of him, he says no.
The man in the middle is asked if he knows what color hat he is wearing, from observation of the man in front of him, he says no.
The man in the front is asked if he knows what color hat he is wearing, from inference, he says yes.
What color hat is he wearing and how does he know?
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