Answer Happy

On a multiple-choice test, each question has 5 possible answers: A, B, C, D, or E. A person taking the test does not know the answer to 12 of the questions and decides to guess on all of them. Use this scenario to answer the following questions.
6) Say the person taking the test gets 4 of the 12 questions correct. In how many different ways can this be done? 7) Which of the following equations will calculate the probability that the person gets exactly 4 of the 12 questions correct? = = = a) P(X = 4) = (. 2)4(.8) 8 b) P(X = 4) = 12C4(. 2)^(.8)8 c) P(X = 4) = 12C4.2)8(.8)4 d) P(X = 4) = 4C8(.2)(.8)8 e) P(X = 4) = 8C46.2)8(.8)4 = = = =