Looking down to the table in the front of the room, the students saw several stands with stuffed and mounted birds. They could see that they were birds, as the feet were visible below the burlap sacks that had been placed over them. And beside each was a small sign with a number.
The bell rang, the professor allowed a moment for the noise to die down, and them addressed the class. "Today's final will count, as you know, for a large percentage of the grade. But the directions for the test are simple. You are to identify each of the birds on the table before you. Write the number, and the latin and common name of the creature associated with it, on your paper. When you have completed the identifications, you may leave. Begin." With that he sat down.
One of the students, a few rows back from the front gestured for the profs attention, and asked a question, "Uh, professor, are you going to remove the sacks so we can see the birds?"
"No... If you've been following the lectures through the term, you should be able to identify each of them by its feet alone. You should have realized the areas that I was stressing, in class and in the reading assignments."
The student, becoming a little alarmed, "You mean, you expect us to be able to know one of these from the others just by its feet. That's unreasonable."
"I'm sorry you're dismayed by this test. Perhaps if you'll begin it'll go better than you expect, and then the others can begin also."
"No, this is absurd. I'm not going to take this test. This is outrageous. I'm leaving." And the student begins to gather up his pencils, and day-pack.
"If you're leaving, tell me your name, so I can mark you off in my book now, please."
The irate student, holding up his feet so the prof can see them, replies, "YOU FIGURE IT OUT!"