This is not a new word puzzle. I first saw it 20-25 years ago. I believe the original wording had a mixing or misuse of tenses that misdirected readers to the technically wrong answer.

I think math guys tend to overlook the mixing of tenses and think nothing of it, while the writing guys focus on the tenses as defining the actual question. The word puzzle itself is a contorted, purposefully confusing presentation. Any editor would demand a rewrite.

As someone who took technical writing and science writing and non-fiction writing and all that, I feel like it's no accomplishment to be able to confuse people. I actually edited some military reports that had a lot in common with this word problem: they were purposefully written to misdirect readers to a wrong conclusion.