A 20-question multiple-choice exam has four possible answers for each question. For each correct answer, you are awarded 5 points. For each incorrect answer, 2 points are subtracted from your score. For answers left blank, no points are added or subtracted. What do you think would be the typical score if you guessed on every question? What is the best possible score you can hope for? What is the worst possible score you can hope for?
Below, we simulate guessing on all 20 questions, making a dot plot of our total scores. As the slider moves form the left to the right, there will be 500 tests simulated.
