In 1986, George Bernard Dantzig himself, told us a fact about his younger days at the Berkeley University, when he was just a PhD candidate (1939).\
One day, he arrived too late to attend his advanced statistics class, so he took a note of the pair of "exercises" that he found on the blackboard, thinking that, as usual, they would have been done by candidates as a standard homework.\
At home, after some hard work, he finally managed to solve them, providing a full proof. Then he gave his manuscript to his professor. He took it, without providing useful comments, but later, about six weeks later, Dantzig received a surprising feedback from that professor, since he told him that, in the meantime, he had written an article based on Dantzig's solutions to the open problems previously written on the blackboard, announcing that they would have been published very soon.