Charlie is undecided whether to take a statistics course or an informatics course. On average, 30% of the students taking a statistics course get an...

 Charlie is undecided whether to take a statistics course or an informatics course. On average, 30% of the students taking a statistics course get an A. On the other hand, 20% of the students get an A in an informatics course. Suppose Charlie wants to decide by flipping a fair coin.

(a) What is the probability that he will get an A in a statistics course?

(b) What is the probability that he will get an A?

(c) If he got an A, what is the probability that he took statistics?