Update: on our end of the year final I got a 59%, then the teacher gave us a 20% curve because we were all failing. So passed with a 79% and an 89% in the class. Score.
You could basically add random patterns at random points in the answer key for random amounts of questions in a row. Like 30-55 is ABABABABABABABABABABA or something that'll throw them off. You could get hilariously creative with that.
Because let's say you noticed the pattern.
At 50 questions for a 100% each question would be worth 2 points. If you just miss the C since you put it as an A, you'd only miss one. That would only take away 2 points from the total.
I had a teacher that used to teach psychology. She once made all the answers C because she wanted to prove how people think that all the answers can't be the same.
"ANOTHER A?!?!?" *sets table on fire*
At 50 questions for a 100% each question would be worth 2 points. If you just miss the C since you put it as an A, you'd only miss one. That would only take away 2 points from the total.