A university class has 21 students: 11 are history majors, 4 are psychology majors, and 6 are art majors. (Each student has only one of these majors.) The professor is planning to select two of the students for a demonstration. The first student will be selected at random, and then the second student will be selected at random from the remaining students. What is the probability that the first student selected is a psychology major and the second student is an art major?