Answer:
Step-by-step explanation:
given that on a six-question multiple-choice test there are five possible answers for each question, of which one is correct and four are incorrect
By mere guessing probability for choosing correct answer = p = 0.2
also each question is independent of the other
Hence if X is the number of correct questions then
X is binomial with p = 0.2 and n = 6
a) being correct on three questions,
=
(b) being correct on four questions,
=
(c) being correct on all six questions
=