A professor I had in college, whose first published result was from a piece of homework he turned in where he incidentally solved an open question about bound on a problem, had a curious habit.
I ended up failing and taking his course again (because I had A Lot going on in college), and thus, noticed something.
Each semester, on one of the assignments in the latter half of the class, he assigned one problem out of, perhaps, 30 in the problem set, where as written, it was actually an open problem, and then a day or two before they were due, he'd send out an "oops, my bad" revised version.
I suspect that this was not an accident, given that it always happened only once.
> A professor I had in college, whose first published result was from a piece of homework he turned in where he incidentally solved an open question about bound on a problem, had a curious habit.
A related anecdote is about George Dantzig (perhaps best known for the simplex algorithm):
> During his study in 1939, Dantzig solved two unproven statistical theorems due to a misunderstanding. Near the beginning of a class, Professor Spława-Neyman wrote two problems on the blackboard. Dantzig arrived late and assumed that they were a homework assignment. According to Dantzig, they "seemed to be a little harder than usual", but a few days later he handed in completed solutions for both problems, still believing that they were an assignment that was overdue. Six weeks later, an excited Spława-Neyman eagerly told him that the "homework" problems he had solved were two of the most famous unsolved problems in statistics.
I ended up failing and taking his course again (because I had A Lot going on in college), and thus, noticed something.
Each semester, on one of the assignments in the latter half of the class, he assigned one problem out of, perhaps, 30 in the problem set, where as written, it was actually an open problem, and then a day or two before they were due, he'd send out an "oops, my bad" revised version.
I suspect that this was not an accident, given that it always happened only once.