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Comment by hgsgm | Hacker News Reader

They difficulty ratings are extremely subjective. Some of the yellows and reds enrichment/contests. Some of the reds are straightforward but tedious trial and error. Then there is a yellow that requires physical and mathematical intuition about bicycle wheels.

Is this really how to get a quant job? A clever high schooler could solve these with hints. I can solve most, but I'm terrible at advanced calculus and statistics.

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>Then there is a yellow that requires physical and mathematical intuition about bicycle wheels.

I got this one "wrong" because I assumed it was possible for the bicycle to skid and so swing the back wheel out of alignment.

There is a type of bicycle that is sometimes used as an intermediate step to riding a unicycle -- it's basically a unicycle for the back wheel of the bike, with a pivoting bar attached to it with a standard front wheel at the end of it.

Or you could describe it as a regular bicycle with a direct-drive, pivoting, rear wheel.

All of which to say that it is a bicycle, and its wheels can make any track you like as long as the front and back tracks are a fixed distance apart.

I got the snowman one “wrong” because the problem didn’t say you couldn’t throw away excess snow. Maybe the lesson is that it’s hard to write word problems.

Generally, if you find a simplification that makes the problem trivial you’re interpreting it wrong and should reconsider.

It’s funny because that’s the opposite of what you’d want in a new hire: you want the engineer to pick a trivial solution rather than over-designing everything, so they can solve more problems for your company.

Ha. Right. I guess it’s just one more way in which the interview is an anti pattern for the behavior we want in a coworker.

Can I Google this? Sorry no.

ChapGPT? Pretend it’s not available.

Use a library? No no no.

Ask for help? Thanks for coming in.

I gave up on that one after finding no non-trivial explanation that made sense to me. I guess in hindsight it makes sense the building material is just given in sphere radius, but that didn't click at the time.

I couldn't make sense of the 100-m race one either. The only thing I could come up with is maybe the clock freezes/race ends when the first person finishes, and the scores are then done by distance to the finish line.

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