Need help with a Statistics for business and economics quiz

When you arrive at your statistics class on a hot Thursday afternoon, your instructor surprises you with an unexpected quiz.

Unfortunately, you haven’t paid any attention to the lecture in the past weeks. The test is multiple choice. It consists of 10 questions, each with 4 possible answer(A,B,C and D).

You decide that your best course of action is to give a random answer to each question (you don’t even bother to read the question or the answer).

a.What is the probability of giving the correct answer to a multiple-choice question with four possible answers?

b. If you give random answer to the 10 questions, how many questions would you expect to have answered correctly? In other words, what is the Expected value?

c. You will pass the test if you answer at least 8 out of 10 questions correctly. What is the probability that you pass the test?