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.

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

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

I've seen variations of #18 before but more involved versions where I've had to write pseudo code to place clock hands based on the current time from a timer.

I've also seen various variations of the Fermi questions before, though maybe not exactly these ones. Like half of the questions listed there fall into that model: Estimate how many XYZ are there in ABC?

Of the others, “How would you direct someone else on how to cook an omelet?” seems pretty reasonable in terms of sussing out communication skills, but a lot of the rest are just insanely stupid questions, IMO.

#18 is kind of interesting, because there's two possible answers. For a modern analogue clock where the hands move in fixed increments, rather than smoothly, the answer is simply 5 minutes. For older ones it's 25/6 minutes.

I like #12, just because it begs to be answered with "perfectly".

#18 actually seems like a real-world problem a programmer might face. Besides, there are coldly logical steps you can take to solve the question, and a closed, correct answer, unlike most of the open-ended waffly answers elsewhere in the list.