The records of Midwestern University show that in one semester, 38% of the students failed mathematics, 27% of the students failed physics, and 9% of the students failed mathematics and physics. A student is selected at random.
a.) If a student failed physics, what is the probability that he or she failed mathematics?
b.) If a student failed mathematics, what is the probability that he or she failed physics?
c.) What is the probability that he or she fails mathematics or physics?