The Hardest Interview Puzzle Question Ever

Oh. And I don’t like soda. Terrible for your health. The number of soda drinkers is probably directly related to the cancer and diabetes rate.

Just FYI :slight_smile:

This is simple - I don’t drink cola (It gives me migraines since I am mildly allergic to the carbonation). So the answer would be None.

Also, StackOverflow user profile is also a good way to judge talent. Not really but amount of points, but the posts you make and how you answer questions tell a lot about the candidate.

Jeff,a lot of the questions you are complaining about aren’t puzzle questions:

How much of your favorite brand of soda is consumed in this state?
how many optometrists are there in Seattle?

These are estimation questions – they require no trick or special knowledge. They have no ‘right’ answer since they are process questions. Because of that, I think they are much better than puzzle questions. And I think one or two questions in an interview assessing the estimation skill of an engineer.

That being said, I completely agree with your general point about puzzle questions

Mecki was the first, but I agree: of course, the answer is 42!

Prisoners/Pirates answer: The monkeys are invisible.


The culture of puzzle questions at Microsoft has to a large extent faded away. I talk to a fair number of interviewers here and I have not even heard of anyone who uses puzzle questions since the 1990’s. I read Poundstone’s book when it was published and it seemed terribly dated even then.

Puzzle questions test your ability to answer puzzle questions, which is not a skill that drives Microsoft shareholder value. It might be correlated to skills that do, but why test for a correlate when we can test directly for the skills that do matter? Like ability to design, implement, test, analyze, debug, maintain and document high quality software.

And, of course, communication is key to all of those things, none of them being done solo.

What you have to remember, Jeff, is that nurses may not want to explain to you what they are doing. You the the right to refuse treatment, which is not necessarily in their (and the hospital’s) best interest. You are under the impression they are looking out for your wants. They aren’t. They are looking out for their employeer’s wants, and that is to keep you from causing problems and sueing them. Most hospitals would prefer that you don’t ask questions and let them do what they think is in your best interest. Communication with you is not key for them to do their job.

I read this before my morning coffee, and I saw:

have the candidate give a 10 minute watercolor presentation to
your team on something they’ve worked on

Which lead to an entire series of amusing mental pictures of geeks with giant paintbrushes and pastel paints, filling the walls of a conference room with watercolors on those giant Post-It notes, then describing the pictures in haiku for the interviewer.

Like the puzzles, it would certainly be amusing, but not very productive.

It seems to me that every company wants to hire the best, the smartest, the ones with communicative skills, la crÈme de la crÈme. Nobody wants to get down to the dirty business of educating his employees.

But where do these smart communicative guys come from, then? Do you have to be born that way? Or is a smart company not the one that hires the cool guys, but that hires the potentials and makes them the cool guys?

That said, I don’t like skill tests in job interviews at all. Test for honesty and attentiveness and everything else can be worked out.

The other kind of interview questions that always bugs me is Give me some examples of how you resolve conflicts in a team. I always struggle to recall the last time I actually had a conflict with my team mates. It is usually implied that if you fail to provide examples, then you are either not experienced in teamwork or you are hiding something that may not be to your favor. In any case, having no particular answer to this question seems to be perceived as something negative.

But on the other hand, can’t it be interpreted in a positive way? Maybe I have no answer because I do not create conflicts and I am good at actually avoiding conflict with others? Or if I am a team leader, maybe I just built the team in such a way that possible conflicts are mitigated? Or I am just lucky to work with really nice people?

I responded to a question on this topic on stack overflow a couple of months ago.
What algorithms should every developer know?

Fortunately I have since never had to have a job interview.
But if someone were to give me such a problem/question now,
I would probably come back politely asking the interviewers to
if we could discuss instead, in what ever detail they desire, my qualifications,
and what I know I can do for their company.
And if we could discuss the corpus of my work, my designs for real programming problems
I have solved, and my passion for programming.

How would that go over?
Is that the type of response the presentation of this type of puzzle question is supposed to elicit?
Otherwise, frankly, I’d be insulted.

Was it just me or did that insanely difficult puzzle question example fail to include an actual problem? It just describes the situation and asks for a solution, without even specifying the intended result and that’s … well that’s something you’d want a PR person to be able to solve. Programmers deal with defined problems.

Personally, if I were asked that puzzle, I’d give the most convoluted possible answer that, likewise, would not contain an actual answer to anything. They would surely hire me for seeing through their stupid game.

I just finished a discrete math class, which I was taking for the second time (run #2 was considerably more reasonable). The first time I took it, some of the questions on the final looked a lot like that one.

Do I fail if I ask what a watercooler presentation is?

I have to agree with Kevin’s simple answer, Good bye.

I no longer accept interviews with companies that don’t ask for a phone screen first. By the end of the phone screen I try to determine whether I gave the company interviewing me enough information to justify hiring me and that of course I want to take the job. If I can’t make those two qualifications I won’t accept an interview. This ensures the interview is on point and hopefully nothing more than a rehash of the phone interview, with a show and tell of how I could bring value to the position added on. This enables me to avoid the stupid where do you see yourself in 10 years and other mindless brain teaser questions.

It’s not worth working for a company that spends its limited interviewing resources asking you mindless brain teasers instead of verifying how you will bring value to it’s bottom line. Those 401k packages and profit sharing plans will be short lived when they haven’t hired anyone who can write actual code.

Finding a great job is not about learning how to job through the next set of hoops that HR creates. It is about ensuring that the company you are interviewing with can identify what skills it needs and making sure you have those skills. Last time I checked, knowing the number of gas stations in the country is not valuable to Microsoft writing a valuable OS. Perhaps that’s why they ditched the practice.

A site I found years ago is excellent at separating sane hiring practices from questionable. I’d suggest anyone with a true interest in how to hire quality people or how to find a job for life to take a look. You’ll never try to move Mount Fuji again.

You solve any puzzle my unzipping and squirting cum on it.

Switzec, If you’d follow the link you’d see that the quoted article starts with Here is a parody puzzle question…

Basically problem solving is making the problem go away, and I assure your that if you take my advice and unzip and blow a load at the problem it will go away