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Interview Question
Posted: Thu Jan 06, 2011 7:17 pm
by Griffen
For all you deep thinkers out there, I had an interview question as follows:
Why are manhole covers round?
This should test your critical thinking / reasoning skills.
Re: Interview Question
Posted: Thu Jan 06, 2011 7:35 pm
by Apadravya
A non circle geometric shape if turned a certain way can fall through, I think.
Re: Interview Question
Posted: Thu Jan 06, 2011 7:37 pm
by puma guy
"zactly"!
Re: Interview Question
Posted: Thu Jan 06, 2011 7:39 pm
by powerboatr
Apadravya wrote:A non circle geometric shape if turned a certain way can fall through, I think.
yup
that's what i was taught in college
round is not prone to falling in the hole.
and its stronger across the middle than a square for example, because the load can be distributed evenly at each edge, where as a square or parallelogram, triangle or some other shape would transmit load to stress points (the corners) and would require a thicker structure
at least that's what i remember but it was long long ago in a land far away
same reason arches are stronger than non arched structures
Re: Interview Question
Posted: Thu Jan 06, 2011 7:42 pm
by Griffen
Apadravya wrote:A non circle geometric shape if turned a certain way can fall through, I think.
I answered because it rolls better than a square. DUH!!
Re: Interview Question
Posted: Thu Jan 06, 2011 7:47 pm
by RPB
Griffen wrote:For all you deep thinkers out there, I had an interview question as follows:
Why are manhole covers round?
This should test your critical thinking / reasoning skills.
Because the hole it fits is round.
It would be silly to make square/triangular covers for round holes now wouldn't it?
Seems quite simple to me ....
now if the question was
Why are manholes and their covers round?
I'd agree with the above answers.
Ok ... my turn to ask one ...
Why do gloves have 4 fingers and a thumb shape?
Re: Interview Question
Posted: Thu Jan 06, 2011 8:03 pm
by i8godzilla
A few years back we had someone that worked for our firm that 'collected' interview questions. (My wife and I own an executive headhunting firm.) Some of the questions that employers ask really baffle us some days. This is one that would fall in to that category.
Unless I was interviewing for a drainage/sanitation or related position, I would have just said not all manhole covers are round.
Check out this cover from the first century AD on Wikipedia:
http://upload.wikimedia.org/wikipedia/c ... rkt-71.JPG" onclick="window.open(this.href);return false;
Re: Interview Question
Posted: Thu Jan 06, 2011 8:04 pm
by RPB
Occam's razor . The simplest answer is usually the correct answer.
That was probably a "can he keep it simple" interview question ... K I S S
Or, could be
how well do you listen to directions and analyze a problem before jumpin' in question.
Some people overthink and complicate things and fail to see an easier solution to a problem.
(My ex-boss did that a lot, usually I'd have to untangle his mess)
Round
covers DO roll easier too, that's not a bad answer at all really
Re: Interview Question
Posted: Thu Jan 06, 2011 8:24 pm
by cbr600
deleted
Re: Interview Question
Posted: Thu Jan 06, 2011 8:52 pm
by C-dub
Admittedly, I'm not a deep thinker, but the non-circular geometric shape thing doesn't make any sense to me. No matter what the shape, if it's small enough it can go through and if not it won't. If that's the answer it still doesn't make sense to me. The stress thing makes much more sense to me.
Re: Interview Question
Posted: Thu Jan 06, 2011 8:59 pm
by Dragonfighter
RPB wrote:Occam's razor . The simplest answer is usually the correct answer.
A small nit to pick, Occam's (William of Ockham) wrote:
entia non sunt multiplicanda praeter necessitatem
"Entities should not be multiplied beyond necessity." Which became known as
"lex parsimoniae" or the "law of parsimony". Colloquially known as Occam's Razor.
Inductive logic lends itself easily to tautology and continuum fallacies (slippery slope arguments). Occam's Razor states that one should not add information to the hypothesis in question without first proving its need. For instance you have a hypothesis and axiom "A" is given, yet it does not complete the hypothesis, so postulate "B" must be introduced and tested as valid. Unnecessary complication would be where we add postulates B, C, D, etc. without first proving postulate A or the necessary elements of complication.
So Occam was noted for saying, "Given two competing theories, the simplest should be given preference." IOW, the more succinct of the two is more easily validated and barring contradictory fact should be accepted. That is where we get, "The simplest answer is usually correct", but it is not Occam's Razor.
Added in Edit:
Admittedly, I'm not a deep thinker, but the non-circular geometric shape thing doesn't make any sense to me. No matter what the shape, if it's small enough it can go through and if not it won't. If that's the answer it still doesn't make sense to me. The stress thing makes much more sense to me.
Because your thinking stacked planes not intersecting ones. Take a square for instance. A 4'x4' lid fits a 4'x4' lip on a manhole. But if you measure the hole diagonally it measures about 5.7 feet. So you drop that heavy four foot lid while moving it and a square side aligns somewhere other than edge to edge and down she goes. Now you have to recover the lid or clean up the brains of your co-worker that was below grade.
Re: Interview Question
Posted: Thu Jan 06, 2011 9:18 pm
by RPB
Dragonfighter
you are absolutely correct .... I just quickly threw that out to illustrate a point
I'm guilty of an
oversimplification resulting in a misstatement of fact about
simplicity,
but it got the point across I think..
I need to find a razor though ... a guy on youtube said I needed one to have a right BARE arm.
Re: Interview Question
Posted: Thu Jan 06, 2011 9:46 pm
by C-dub
Now it makes sense. I wasn't thinking about the lid itself. Duh!
Re: Interview Question
Posted: Thu Jan 06, 2011 9:51 pm
by Griffen
You folks are right, on more than one level...
http://en.wikipedia.org/wiki/Manhole_cover" onclick="window.open(this.href);return false;
However, the point about a race car creating enough vacumn to lift a manhole cover is equivalent to aliens killing birds in AK.
Re: Interview Question
Posted: Thu Jan 06, 2011 10:08 pm
by RPB
Griffen wrote:You folks are right, on more than one level...
http://en.wikipedia.org/wiki/Manhole_cover" onclick="window.open(this.href);return false;
However, the point about a race car creating enough vacumn to lift a manhole cover is equivalent to aliens killing birds in AK.
Yeah, I'm pragmatic ... Yes, that was a Microsoft Interview Question ... I worked for and with MSN/Microsoft too, and while there, hired and fired people too
Oddly, I "flunked out" on the first interview, they were impressed and called me to interview again, but for a new position which they created just for me.... which ended up eventually being much more powerful as I later hired fired, trained and supervised people for the position for which I flunked out of the first interview.
(I didn't know that info was on Wikipedia though lol)
From footnote on your link ....
http://en.wikipedia.org/wiki/Microsoft_interview" onclick="window.open(this.href);return false;
How would you test an elevator?
(Where's my EX-wife?)
How would you explain computer networking to a kindergarten kid?
(Seems like I did that a lot numerous times)
What are examples of poorly designed software?
(Windows 3.0, Windows 3.1, Windows for Workgroups ... how many do you want? I use OS/2, but I can probably name a lot more if you want me to ...)
(As I said ... I "flunked out" on the first interview)
It was fun though, Just for fun, not part of my job there ...I'd take the "answers" to their certification exam questions, and suggest shorter/faster ways to accomplish the same task.... They enjoy people seeing "multiple" solutions to problems.