Of students in the AP curriculum at a prep school, 40% take one AP exam, 45% take two AP exams, and the remaining 15% take 3 AP exams. The highly desirable score of 5 is hard to earn, and only 20% of these students will earn a 5 on any given exam they take. Assuming their results on each exam are independent, what is the probability a student in the AP curriculum will earn at least one 5