A section of an exam contains five true-false questions. A completed exam paper is selected at random, and the answers are recorded. Write each answer using a fraction.

a. Assuming the outcomes to be equally likely, find the probability that all answers are true.

b. Assuming the outcomes to be equally likely, find the probability that exactly three of the five answers are false.

c. Assuming the outcomes to be equally likely, find the probability that all the answers are the same.

d. Assuming the outcomes to be equally likely, find the probability that at least one answer is false.