I had a professor in calculus. His tests were multiple-choice, with 1.0 for correct and -0.25 for every wrong answer. So even if you answered _nothing_, you would get a 0.
The average in his exams used to be -1.5 or so. You made an "A" if you got > 2.5 out of 15.0
That is the point! People were just too proud to leave the test blank; they thought they knew the material. But the wily old fox would trick them, and very few saw through this tricks.
I had a professor in calculus. His tests were multiple-choice, with 1.0 for correct and -0.25 for every wrong answer. So even if you answered _nothing_, you would get a 0.
The average in his exams used to be -1.5 or so. You made an "A" if you got > 2.5 out of 15.0