Question

In a multiple-choice test, each question has five options. Students will get 5 points for each correct answer; lose 2 point for each incorrect answer; and receive no points for unanswered questions. A student does not know the correct answer for one question. Is it to her advantage or disadvantage to guess an answer? Show your calculations for expected value

Answer 1

I would say that it is to her disadvantage because if you guess an answer and get it wrong then you lose 2 points but if you don't put anything then you don't gain any points or lose any points. There is a chance she would most likely get it wrong if she guessed, So i would have to say not guessing is the better way to go if you arent going to lose any points for putting no answer.

This was a really confusing question so im not sure that my answer is correct but i tried answering it as best as i could... sorry :(

Answer 2

But actually now that i think of it, i think im right because she has a 75% chance its wrong. And she would lose 2 points.