13. Tanya is planning her schedule for university. She wants to take the following courses during her first two terms: biology, English, psychology, religion, linear algebra, political studies, economics, and philosophy. She is equally likely to take any of these courses in either term, since they are all introductory courses. a) Suppose that Tanya decides to take four courses in her rst term. Determine the probability that three of them will be psychology, linear algebra, and English. b) Suppose that Tanya decides to take ve courses in her rst term. Determine the probability that three of them will be religion, political studies, and biology