When I was a Math/Chem grad student at Princeton in 1973-74, there was
a story going around about a grad student. This guy was always late.
One day he stumbled into class late, saw seven problems written on the
board, and wrote them down. As the week went on he began to panic:
the math department at Princeton is fiercely competitive, and here he
was unable to do most of a simple homework assignment! When the next
class rolled around he only had solved two of the problems, although
he had a pretty good idea of how to solve a third but not enough time
to complete it.
When he dejectedly flung his partial assignment on the prof's desk,
the prof asked him "What's that?" "The homework." "What homework?"
Eventually it came out that what the prof had written on the board
were the seven most important unsolved problems in the field.
This is largely an academic legend, at least according to Jan Harold
Brunvand, the author of a series of books on so-called Urban Legends.
He talks about it in his latest book _Curses! Broiled Again!_ in the
chapter entitled "The Unsolvable Math Problem." It is, however, based
in some fact. The Stanford mathematician, George B. Danzig,
apparently managed to solve two statistics problems previously
unsolved under similar circumstances.