Question

In a multiple-choice test, each question has four options. Students will get 4 points for each correct answer; lose 1 point for each incorrect answer; and receive no point for unanswered question. A student does not know the correct answer for one question. Is it to her advantage or disadvantage to guess an answer?

Answer 1

well, since you don't lose any points for not answering, I would say do not answer.

Reason being, you have a 1/4 chance of being right, and 3/4 chance of being wrong.

Sure, it's much better if you can guess it correctly, but you have 3 times the chance of being wrong rather than right.

So it's best to just not answer and find another question you can.

[this is also the reason most tests you take mark down points for non-answered questions]

Answer 2

You wont receive any points for unanswered questions

Answer 3

that's exactly why its (in my reasoning) not good to answer if you don't know the correct answer.

there are many ways to look at this really.

if you only don't know the answer for one question, it's probably fine to guess assuming all your others were correct.

if you don't know the answer for many questions, it's probably bad to guess because you will have the chance of losing more points than you gain

bottom line -
assuming the student does fine on all other questions, it's okay to guess on one or two. But the more questions you are unsure of, and the more you guess, it is much more likely that you will lose points in the long run instead of gain them.