On a clock or watch, how often do the hour and minute hands align?

None of the above

It's a fun exercise. One can solve this perhaps more easily by pretending to sit on the hour hand, then only one of them moves.

Wat answer 🧌

It is one of the above

After voting I Googled it and it totally makes sense, I feel like an idiot

Okay folks, here's the answer. I'm not even going to try to pretend I knew this before today. I was curious, and my initial thought was 65 minutes. But congratulate yourself if you selected answer C (at least according to the variety of sources I checked). Supposedly, it works like this: The minute and hour hands align 11 times every 12 hours (= 22 times per day). Why not 12 times? Well, just as the minute hand passes 11, the hour hand is already nearly at 12, so they never catch up until they reach 12. The formula is 12 hours / 11 intervals * 60 minutes = 65.45455 minutes per interval (actually 65.4545454545455 to be even more precise). Something you can now share at parties.

Because C wasn't precise enough? Or some other answer?

Right there with you!

If you are wearing a Seiko then never. 😂 Sorry didn't mean to crack on their quality control issues. 😂

Shots fired across the bow!! Here we go!

More often than is said here. I think it might also depend on the type of clock one uses, Such as a 6 hour clock, a 12 hour clock, or a 24 hour clock

NEVER!

Let's give that man a hand!

I used to use a variant of this as an interview question before I decided that it’s more revealing of me than the candidate.

Man do I love AI. However, it explained it all to me in ways most people would never comprehend. 😝 Here’s what Chat GPT spit out.

I can't do the math, but when I was a student, I was very good at multiple choice tests. In high school, had the SAT score for Harvard, and the GPA for Arizona State!

I'm glad I didn't see that explanation first! Translating to degrees seems like an unnecessary step. But math was never my strong suit.

I mean if you're going to arbitrarily round to some number of decimal places, you might as well count B and C. Better yet, you can't really measure half minutes on a watch, so scientifically it would have to be every 65.

I didn't actually intend to round off. I used Excel as my calculator, and didn't realize until after the first post that there were additional trailing digits omitted by number formatting. To me the concept is more interesting than the precise number.

65.

Every 65 minutes and 27 seconds.

Yep, as far as I'm aware, that's correct. Essentially the same as answer C.

I think it requires some mental convincing that the hour hand aligns 22 times per day. Inspired by Lagrangian flow, here is what I deem the simplest solution, but I may be wrong.

To an observer on the hour hand the minute hand will have moved "55 minutes" within one hour. We know that is true because it will go from 12 to 1 o'clock so they are exactly one "hour gap" apart. In other words, the minute hand makes 11/12 revolutions per hour (to that observer). So it takes 12/11 hours to make a full revolution. Seeing how a full revolution occurs exactly when they align and converting to minutes we get

It took me a moment to understand the observer concept. I guess a simpler approach would be to keep everything in terms of minutes.  Each time the minute hand moves 60 minutes, the hour hand only moves 5, so the relative difference between the two hands per hour is 55 minutes.  60 / 55 x 60  =  65.454545454545