Can you solve this riddle Elon Musk asks job applicants?

boing
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You are using an assumption from the first line(s)s and applying it to the last line.

The first line says you are standing on Earth. The next lines do not necessarily have that restriction. The walking part does have directions related to something with directions such as a celestial object, not necessarily Earth. The last line doesn’t require any relationship to Earth or even anything with directions. It just say “You end up exactly where you started.” It does not say how you got there. Or when or preclude any intervening actions.

But for fun, if all lines require that you are on Earth, then there are other quirky possibilities:

  • In jail (after escaping, wandering, being captured, and returned)
  • Next to a wormhole that returned me to my initial position
  • I’m -insert mental state-
  • “Standing on the surface of the Earth.”
  • In the SpaceX interview room
  • Sitting in front of my laptop responding to Wazroth
  • Looking for the building manager so I can trade him this fine barometer.
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85

broadchurch-who-let-you-in|nullxnull

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86

They do.

Cardinal directions in geographic navigation are necessarily restricted to meridians (for north/south) and parallels (for east-west). You MIGHT have an argument if the thing said “You start walking East” or something, because then you could imagine a scenario where you begin in a compass direction of East but follow a great circle and begin deviating from purely Eastward navigation due to the curvature, but it says “You walk East”. With no other modifiers this restricts the movement to being along the parallel for the entirety of the movement, not to mention on the surface of the planet.

87

Those aren’t my shoes.

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88

Those aren’t my feet.

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89

Nice job taking my quote out of context, then quoting only the second line from Pesco, then arguing your point, which I didn’t disagree with.

None of which matters since the final line is “You end up exactly where you started.”

The Earth moves through space. The only way you can end up exact where you started is if aren’t on Earth. Or do you subscribe to the geocentric model of the universe with the Earth as stationary?

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If you assume that Earth’s motion through the universe means you are never in the same place twice, then your property deed is invalid and I can commandeer your house, right?

91

That’s still a pedantic bridge too far. Once we’ve established our reference frame as navigation on the Earth’s surface, the meaning of “exactly where you started” is fixed, and it’s in the context of the same reference frame.

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I like your thinking, but no. Property lines are surveyed with respect to survey markers, which move with the Earth. It’s also nice they move with tectonic movements. Survey marker - Wikipedia

That and I’ll kick your behind if you take my house!

Thank you. I’ll take my half black sheep and go home now.

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93

I’d have to go the ‘conquest’ route then, same as Europeans in the Americas.

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My old boss used to ask people how much the building weighed. According to him it was to see how the applicant approached a problem.

Still seemed kind of bullshitty to me.

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95

I have no problem with hypotheticals, but FFS make it a hypothetical relevant to the job at hand, not just some abstract brain teaser. I find things like this are more for the benefit of the interviewer’s ego than to really judge the potential of an applicant.

I consider myself reasonably intelligent but I tend to struggle with highly abstract concepts, and as such I can tend to get frustrated with brain teasers and riddles as a result. Once I hear the solution it’s often a “well, no shit” moment. I guess it all depends on the person.

For someone who’s more “big picture” I would guess these kind of answer come easier than to someone who tends to stick with the finer details (and I definitely fall into the latter group). I guess stories like this are kind of triggering to me because of my impostor syndrome and general intolerance for this kind of “look at how clever I am” bullshit.

96

I’m guessing the intersection of “people who read books full of brain teasers as a hobby” and really good [ engineers | programmers | artists | other creatives ] is significant.

Depends a lot on how the answer is allowed. If the interviewer just wants a correct answer, then useless. Probably asked by an HR drone who doesn’t understand the question or answer.

But if they allow open thinking, provide a whiteboard for sketching, etc., and will listen and evaluate the interviewee’s efforts at thinking through the process even if the answer is wrong, then a useful tool.

[threadjack on]
The few times I was dragged into interviewing, I had a simple question about PLC logic. Two rungs that did the same function; one that could be written in one line but was kinda tricky to understand, and the other being 4 lines long but much easier to understand. The question was to explain which is better from a long term, quality software point of view.

| *** compact, but not intuitive
|---(/)---(/)---(/)--(/)----------------------------o(  )---|
|   B1    B2    B3   B4                               L1

| *** bulky, but very easy to understand
|---( )---+------------------------------------------(  )---|
|    B1   |                                           L1
|---( )---|
|    B2   |
|---( )---|
|    B3   |
|---( )---|
|    B4   |

Both these rungs compile to the same size, run at the same speed, and accomplish the same thing: if any of buttons B1, B2, B3, or B4 are pressed, turn on light L1.

What makes the first, more compact, rung tricky to some is the use of the NOT on the output ( —o( )-- ); to me, and many people I’ve asked, it’s not easy to determine what it does. Whereas the 2nd rung can be understood by almost anyone, even non-programmers with a bit of help.

Anyone who explained that the 2nd example was better since it would be easier to understand got my vote. Those that thought it was better to use “clever” code even at the expensive of understanding got a thumbs down.

And I’ve had a few heated arguments with “programmers” that felt if you don’t have the chops to understand tricky code, you shouldn’t be programming.

This was in the 1980s to 2000s, before agile, before “move fast, break things” mentality. It was also on multi-million$ heavy machine tools, when “breaking things” could hurt. Or cost. A lot.

Sorry for the thread highjack. I have no idea why I went on about this. I’m an old? Bored?

On topic: IMHO, Elon Musk is both brilliant and an idiot.

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97

Ahem. AT LEAST half-black.

98

Whenever I’ve had to do technical interviews for a non-vendor position, I tend to use a simple but rather open-ended coding question but with intentionally vague requirements. I would expect even a junior person to get through the coding part, but what I’m more interested in is the thinking beyond just the code.

Do they just whiteboard some code and think they are done? Given the vague “spec”, do they ask clarifying questions? Do they also think about testing, performance, i18n, and security? The more senior the position, the more of these things I would expect of them.

Hiring should be based on the potential of the applicant, not the ego of the interviewer. If I make an interview about me as an interviewer, I feel like I’m doing the applicant a disservice.

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image

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Aha, but the problem does not say you face West and walk straight for a mile. It says you walk West for a mile. If that necesstiates following a path that doesn’t stick to a Great Circle, so be it.

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Yes, I was responding to @soimless positing that their solution worked if the compass direction were only followed at the start of each mile of walking.

102

If you include MGRS there are three north poles: Magnetic north, true north (the point around which the earth rotates in real life), and grid north (the point around which the earth rotated in 1984 which standardizes where the grid lines would converge)

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103

Aha. Retracted!

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