Of the students at a certain college, 50% regularly attend the football games, 40% are first-year students, and 40% are upper-class students who do not regularly attend football games. Suppose that a student is selected at random.
(a) What is the probability that the person both is a first-year student and regularly attends football games?
(b) What is the conditional probability that the person regularly attends football games given that he is a first-year student?
(c) What is the conditional probability that the person is a first-year student given that he regularly attends football games?