My question about a snail climbing out of a well was closed as off topic and deleted, because

[...] it appears to be a mathematics problem, as opposed to a mathematical puzzle.

The Question

A snail finds itself at the bottom of a 30 foot well. It crawls up 3 feet each day, but at night, while sleeping, it slides down 2 feet.

How long does it take for the snail to crawl out of the well?

The Answer

The snail climbs at a net pace of a foot per 24 hours, so the naive answer would be 30 days.

However, after 27 days, it finds itself at 3 feet from the top. After having crawled the remaining 3 feet on the next day, it's already out of the well and no longer slips down!
This makes the correct answer 28 days.

A recent answer on meta regarding mathematical puzzles reads

[...] that "a-ha!" moment, [as] that's exactly what makes puzzles fun and enjoyable to solve!

and cites chat

Math is not off-topic. But math with no "aha moment" is.

In light of that, I contend that the question about the snail does contain such an a-ha! moment and as such should be on topic.

Can it please be undeleted and re-opened?


1 Answer 1


I wrote the answer you are looking to for your question's redemption. The comments that came from your question and its (self-)answer are still true and in my opinion fully justify the question being closed. In particular, this telling comment:

@SQB I don't want to be rude, but that twist is so trivial I'm not sure you can really call this a good puzzle. That being said, I am glad you answered it yourself.

As the Meta answer says, "we want the focus of the puzzle to be the puzzle". I agree with the comment writer - that trivial "twist" does not a puzzle make; it's not enough "a-ha" to redeem the posting as anything substantively more than a simple exercise in arithmetic. Closure seems to me to have been appropriate.

Deletion was a consequence of the closure, and seems equally appropriate. The self-answer doesn't help your case either - it's immaterial to the discussion of whether or not the question is on-topic, but it (and your own comment!) suggests the intent here was not to provide the community with a puzzle but rather to air a bit of mathematical trivia, and was (probably justifiably) not well received by the community. The downvotes coincident with the closure led to the question's subsequent deletion.

Those are my thoughts. We'll see if the community feels otherwise.

  • $\begingroup$ The intent was not to "air a bit of mathematical trivia", but to provide an example of a discussion at the time, whether we wanted self-answered classic puzzles here or not. Perhaps the question should be reopened, but locked as "historical" (as is done on SO). $\endgroup$
    – SQB
    Commented Jul 29, 2017 at 9:13

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