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 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

4(1/4)+-1(3/4)
1-3/4
(4-3)/4
1/4
i think its an advantage
not sure :(

Answer 2

thanks mathematicalpro