
Wacky interview questions - aaronbrethorst
http://www.geekwire.com/2013/cows-canada-24-wacky-interview-questions-amazon-google/#utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+geekwire+%28GeekWire%29&utm_content=Google+Reader
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MattRogish
These aren't just wacky, they are stupid. "How many ping-pong balls can fit in
a VW bus" is just about the worst question I've ever gotten. Little or no
relation to software development.

Here's what we do. Interested in feedback, please!

Via the phone:

* A few background questions (why are you looking for a job, what sounds interesting about what we are doing) (20-30 minutes)

* A bunch of topgrading questions <http://www.smarttopgrading.com/> (maybe an hour)

In person:

* A few programming challenges (of increasing difficulty) that involve stuff the candiate is not expected to know (some algorithmic, most problem-solving type thing), and has to solve it via Google and Stack Overflow or whatnot, to make sure they can work outside of their comfort zone (I've had a lot of people freeze up at "Write a program to get Time from outside of the system", for example) (couple of hours til lunchtime)

* Then pair programming for the rest of the day to make sure we can all get along with this person (after lunch, and next day if possible)

If reasonable, we put a new hire on a 1 month contract before we make a final
offer (we give a tentative salary offer at day one so they know approximately
what it'll be but cannot judge equity grants until we have more time with
them).

~~~
IvyMike
> "How many ping-pong balls can fit in a VW bus" is just about the worst
> question I've ever gotten.

The point of questions like this is "Does this guy have any common sense?"
Some of my least favorite hires were people who were whip-sharp at the details
of their chosen programming language, but then when hired, would go off and do
crazy and impractical stuff with it.

Whether or not the question accomplishes a good evaluation of someone's common
sense is up for debate, but unless you're hiring drones, you do have to ask
some questions that get a broader picture of the way the person thinks.

(BTW, your "pair programming for the rest of the day" is a great way of
getting that. But pair programming doesn't/wouldn't work at any place I've
ever been, for a variety of reasons.)

~~~
columbo
> The point of questions like this is "Does this guy have any common sense?"

 __GROOOOOAAAAN __

Maybe twenty years ago, and maybe if you were the individual to think up the
question.

Honestly I'm so goddamned bored with these unoriginal blither-blather
questions I consider them a strike against the interviewer and the company.

~~~
IvyMike
I actually have never asked an estimation question, but I understand the
motivation for asking this kind of question.

I'm curious--what do you ask in interviews to get at a candidate's common
sense? It's not very easy to do.

Or do you think you don't need to assess common sense at all? Maybe it's not,
but like I said, a lot of the hires I later regretted came down to something
like that.

~~~
columbo
> Or do you think you don't need to assess common sense at all?

 _shrug_ If we're talking developers... The ability to drive to the location
on time, answer questions without going blank are good indicators of common
sense for me. Extracurricular activities, anything from volunteering at an
animal shelter, to making civil war models to home brewing beer, are huge in
my book because they are a good indicator of a grounded individual. That mixed
with some pair-programming should give more than enough information. YMMV.

------
groby_b
_“What’s your favorite song? Perform it for us now.”_

I'd have to go with "Take this job and shove it". There's nothing worse than
places that mandate you be "fun" and "offbeat". If I _am_ fun/offbeat, all you
as an interviewer have to do is make me comfortable enough to show it. If you
can't do that, why do I want to work for you?

~~~
omd
It could be part of the job description, not every interview is for a
developer.

~~~
dalke
It was for a company which does "Advertising & Marketing Services."

------
famousactress
I don't really ask these kinds of questions, but I do kind of like them.. the
giant puzzle/estimation types. Can someone who asks these regularly give some
feedback on how well you think they work? I'm curious how much you end up
learning from them.

That said, there are some doozies in this list. For example: _"On a scale of
one to ten, rate me as an interviewer"._

Um, okay but only if the next question is to rate you as an asshole.

~~~
crntaylor
I once interviewed at a place that had an interesting spin. They gave me three
fermi questions, which I had 5 minutes total to estimate:

1\. Mass of the earth in kg 2\. US GDP 3\. Number of carriages on the London
Underground

I then had to give a 95% confidence interval for each one (i.e. an interval
that I was 95% sure the true answer lay in) and then asked, for each estimate,
which bet I wanted to take:

1\. Bet that the answer is inside the interval at odds of 10 to 1 on. 2\. Bet
that the answer is outside the interval at odds of 30 to 1.

There's a lot of work that has to be done there, and potential for a very
interesting discussion (this was for a trading/research role, rather than a
software developer role).

~~~
dalke
Which would be more impressive: that I long ago memorized that the Earth's
mass is about ~5.98E24 kg or that I could estimate it knowing Kepler's third
law (T-squared = C * R-cubed) and orbital information about the
Moon(28d@250,000miles), Earth (365d@1AU), and Mercury (88d@0.4AU), where
1AU=93million miles. Or that I could cross-check it by knowing the
circumference of 25,000 miles to get the approximate volume, and knowing that
the density is around 5tons/cubic meter? Or I could use the orbital numbers to
estimate G then knowing that Earth's surface gravity is 9.81m/s/s then I can
also get M_earth.

All of those involve memorized numbers, and most require physics knowledge.
But I have a feeling that the more complicated ones would impress them more,
and make them more likely to hire me. If that's the case, then my strategy is
not to give the answer which I know, but to exaggerate the difficulty by
hiding my actual knowledge.

GDP? It's about the size of the debt, which is something like 7 trillion, so I
would have estimated $10 trillion. (Actually, the debt is $12, and the GDP is
$15.) I might have double-checked my answer because I think the budget is
about $4 trillion, and 20% of GDP giving $20 trillion. (Actually 3.54 trillion
and 22.6% GDP).

How is this memorized knowledge useful? Especially since I don't know how the
GDP is actually calculated? Nor the difference between GNP and GDP. So this
mostly tests to see if I've paid attention to the economic news. It's almost
like asking me if I know the hottest temperature ever recorded in Death
Valley.

And as for the London Underground - too many variables for me to even
estimate. Turns out to be 4134, and that what I thought was part of the
Underground was actually rail services. If forced, I think would have said: 20
rail lines? (Actually, 11.) At rush hour, 10 cars separated by 5 minutes
distance, for a total of about 90 minutes per line? Which gives 3600 cars. I
probably would have rounded up to 4,000 for spares, and then been amazed at
how close I was. (Ahh, I forgot the factor of two because trains are going in
both directions. And I think the inter-train spacing is less than 5 minutes on
some of the lines.)

But this only works because I've been to London and made those observations.
Without that experience, I would be off by an order of magnitude.

So there you go - this proves that I have a degree in physics, that I follow
the news, and that I've visited London. It helps with the job you applied to
because ... ?

(And if you say it's because I can reason about these sorts of problems, then,
see "have a degree in physics" and add "and also math.")

~~~
crntaylor
Almost all of the interesting stuff comes _after_ you've made your estimates
(although the process of getting to the estimates is not completely
uninformative).

If the candidate performs well on this question, then they have shown:

1\. They have the ability to reason about problems in a potentially new
domain.

2\. They have the ability to pare down a problem to what is important and what
can be neglected.

3\. They can make good order-of-magnitude estimates (very important for an
equities trader).

4\. They are aware of the typical size of their errors, or can estimate them.

5\. The are aware of the typical _sources_ of error.

6\. They understand the notion of a confidence interval and can apply it to
real-world situations.

7\. They can reason about bets with different characteristics (e.g. different
expected value, different skew characteristics) and choose a good portfolio of
bets.

I think that knowing how GDP is calculated is useful information for someone
working in finance. Especially someone who is going to have to trade through
economic announcements. Would you hire a trader who _didn't_ follow economic
news?

PS re "shows you've visited London" - the interview was _in_ London. I assume
if it had been in New York, they would have asked about the New York metro.

~~~
dalke
I passed the first test on rote memorization. The second was nearly the same.
Only the third would have given information about my ability to estimate,
which isn't enough to give real information about those 7 bullet points. I
remain doubtful about the utility of these tests.

There is nothing, for example, which probes my experience with statistics.

Here's a more in-depth test. We run an medical experiment on lab rats. The
protocol says that we will experiment on 20 rats, and that a mortality rate
above 30% is too high so we must stop the experiment. After 5 rats, 2 have
died. Should we stop the experiment now? Why or why not?

One could look at that and say that a 2/5=40%>30% so of course it should be
stopped - it's higher than the allowed rate.

A better response is to point out that if 10% is acceptable, then there's a
0.9^3 * 0.1^2 * C(5,3) = 7% chance that this is an expected statistical
fluctuation, and that the experimental protocols should have given some
guideline on how certain one needs to be in knowing if the mortality rate was
too high.

An even better response would be to point out that this means the first three
rats lived, and it was only rats 4 and 5 which died, as otherwise the
experiment would have stopped earlier under this protocol. In that case the
possible experimental states are: 1) first rat died, so the experiment stopped
= p. 2) first lived, second died, stop = p. 3) first lived, second lived,
third died, stop = p. 4) first, second, third lived, fourth died, fifth lived
= (1-p). and 5) first, second, third lived, fourth and fifth died = p giving
(assuming I recall how to do this correctly) p+p+p+(1-p)+p = 1.0 or an
estimated mortality rate of p=0.3.

In other words, this experiment is allowed to keep on going under the given
protocol.

But this sort of modeling awareness is not present in the three tests you
mentioned, despite being directly relevant, I assume, to what a trader does.

~~~
crntaylor
Yes, this kind of statistical modelling is certainly very relevant. I don't
want to give the impression that this was the only question I was asked, or
that it covers everything you need to know about a candidate. The entire
question and discussion took about 15 minutes. I was asked questions of a
similar kind to the one you propose in the other 11.75 hours of interviews.

------
scrumper
I can see where most of these are coming from. Estimation, consulting/sales,
personality, management & leadership. The penguin in the sombrero is harder to
pin down. Are they trying to see how you analyse novel situations? As in,
"Well, it's wearing a sombrero but comes from the antarctic, so it's likely
been on holiday. Since this office isn't in Mexico or the antarctic it's
probably on a travelling holiday, which means its young and doesn't have any
money. Since it's a construction company, best case is it wants a job as a
labourer. Worst case, it wants to use the phone to call its parents and ask
for a bail out." I know, call me Sherlock. I expect I've missed the point
though. I really would like to know what other people have to say about this
question.

~~~
pavel_lishin
> The penguin in the sombrero is harder to pin down.

My response would be, "If a penguin in a sombrero walks through the door and
starts talking, the most plausible reason for why he's here is that you've
spiked my coffee with LSD."

------
minimaxir
_“Have you ever stolen a pen from work?”_

The correct response to this question is to say "Could I please hold your
pen?", and wink slyly.

~~~
pavel_lishin
This reminds me, I lost my pen and it's time to grab a new one.

I consider it stealing as much as I consider using the toilet paper they
provide for me stealing.

------
codegeek
"If you had turned you cell phone to silent, and it rang really loudly despite
it being on silent, what would you tell me?"

Go see an ENT specialist.

------
bennyg
“Calculate the angle of two clock pointers when time is 11:50."

I know the correct answer is supposed to be 0, but the hour hand moves closer
to hour+1 as minutes approach 60. I guess I would ask for a compass.

Another fave is: “How many quarters would you need to reach the height of the
Empire State building?”

My answer would be: "What's the price of admission?"

~~~
crntaylor
The minute hand is at 300 degrees and the hour hand is at 354 degrees, so the
correct answer is 54 degrees (subject to me not having messed up the
arithmetic).

~~~
thinkstoomuch
Interesting, I come out to 55 degrees this way:

30 degrees between hours. 10 is at 300 degrees, 11 is 330 degrees. 50 minutes
into the hour is 5/6 of 30 or 25. 330+25 == 355.

~~~
crntaylor
You're totally right, of course. I originally wrote 55 degrees (using exactly
your argument) then looked at an actual clock and edited my post.
Overthinking...

------
mikeevans
Has anyone been asked any of these? I'm curious because I've been asked #18
before.

~~~
objclxt
I am pretty sure (and given this is HN I'm sure a googler will be along soon
to confirm/deny this) that Google have a policy of no longer asking those kind
of brain-teasers for their software engineering roles. They may still do so
for PMs, etc.

Certainly when I had my Google on-site for an engineering role I was spared
the infamous questions that crop up in articles like this from time to time.

~~~
nollidge
Boy, I hope so. I've got my on-site on Monday!

~~~
objclxt
Hope it goes well for you! Even if, like me, you don't end up with an offer I
think they're fantastic experience.

------
olgeni
> How many diapers does America go through in one month?

"One too many, if you make me work on J2EE."

------
codegeek
"How would you rate your memory?"

Sorry what was that again? I forgot what you asked

------
orangethirty
M$: 1.Define diaper. As in adult, children, paper, cloth, etc. 2.So it doesnt
fall down the hole it is covering.

Amazon: Depends on how much PHP I have to write.

Google: Define cow. Does it only apply to the common animal or does it also
apply to the slang used to refer to overweight people?

Zillow: Define success.

Expedia: Which language version for the T9 keypad? In what language do the
words have to be found?

“If you were to get rid of one state in the US, which would it be and why?

Define "rid".

“How many cows are in Canada?”

Define cow. Does it only apply to the common animal or does it also apply to
the slang used to refer to overweight people?

“How many quarters would you need to reach the height of the Empire State
building?”

Define the specific quarter used for the exercise. Also, tell me the
temperature at which the exercise will be done.

“A penguin walks through that door right now wearing a sombrero. What does he
say and why is he here?

What type of penguin, and sombrero?

“What songs best describes your work ethic?”

What genres are allowed?

“Jeff Bezos walks into your office and says you can have a million dollars to
launch your best entrepreneurial idea. What is it?”

Define best.

“What do you think about when you are alone in your car?”

Is the car ON? Am I driving somewhere? If so, Where?

“How would you rate your memory?”

Which type of memory (short/mid/long-term?)?

“Name 3 previous Nobel Prize Winners.”

Can it be for the same Nobel Prize?

“Can you say: ’Peter Pepper Picked a Pickled Pepper’ and cross-sell a washing
machine at the same time?”

When do you want the Washing Machine delivered?

“If we came to your house for dinner, what would you prepare for us?”

Are you allergic to any type of food?

“How would people communicate in a perfect world?”

Define perfect world.

“How do you make a tuna sandwich?”

Which type of tuna sandwhich?

“My wife and I are going on vacation, where would you recommend?”

Are you going together?

“You are a head chef at a restaurant and your team has been selected to be on
Iron Chef. How do you prepare your team for the competition and how do you
leverage the competition for your restaurant?

When is the competition?

“Estimate how many windows are in New York.”

Are we refering to regular windows or computing devices running the operating
system Windows? Plus, define Window. Is it an opening in a wall? Does it need
to have a glass plane?

“What’s your favorite song? Perform it for us now.” Define favorite (as in top
10 ranking, overall, etc.). Define perform (sing, sing+dance, dance, mime,
etc.).

“Calculate the angle of two clock pointers when time is 11:50.”

AM or PM?

“Have you ever stolen a pen from work?”

Define stolen.

“Pick two celebrities to be your parents.”

Define celebrities.

“What kitchen utensil would you be?”

Define utensil (mechanical, electric, electronic, etc). Define kitchen
(commercial, American, European, etc.).

“If you had turned you cell phone to silent, and it rang really loudly despite
it being on silent, what would you tell me?”

Which cellphone (brand, type, OS, etc)?

“On a scale from one to ten, rate me as an interviewer.”

Does the scale go from best to worst or otherwise?

“If you could be anyone else, who would it be?”

Define be.

“How would you direct someone else on how to cook an omelet?”

Are they disabled in any way?

~~~
doktrin
>“Estimate how many windows are in New York.”

>Are we refering to regular windows or computing devices running the operating
system Windows? Plus, define Window. Is it an opening in a wall? Does it need
to have a glass plane?

>“How would you direct someone else on how to cook an omelet?”

>Are they disabled in any way?

>“If we came to your house for dinner, what would you prepare for us?”

>Are you allergic to any type of food?

>“My wife and I are going on vacation, where would you recommend?”

>Are you going together?

I actually quite liked these answers, and I would think positively of a
candidate who asked them (assuming I would ask the questions in the first
place, which is unlikely).

While "Define this that and the other ad nauseum" is probably overly pedantic,
the above do illustrate an ability and propensity both for analysis as well as
even perhaps empathy - both, IMO, meaningful skills when developing a product.

~~~
orangethirty
Its all in good humor, but it shows that I've been involved in product
development/marketing for a _while_. I'm particularly proud of the "my wife
and I are going on vacation" answer, because I was actually asked that one in
real life by a friend. I replied the same way. His response was to laugh
histerically. :)

