Table 1 shows the number of students enrolled in each of three science courses at Gotham College. Although no students are enrolled in all three courses, 15 are enrolled in both chemistry and physics, 10 are enrolled in both physics and biology, and 5 are enrolled in both biology and chemistry. How many students are enrolled in at least one of these science courses?
Table 1
Course Enrollment
Chemistry...........................60
Physics................................40
Biology...............................30