A true/false test has 40 questions. If a students is simply guessing at the answers,
a. What is the probability of guessing correctly for any one question?
b. On average, how many questions would the student get correct for the entire test?
c. What is the probability that the student would get more than 25 answers correct simply by guessing?
d. What is the probability that the student would get 25 or more answers correct simply by guessing?