If 3 out of 20 students live on campus how much if there are 6000 students?

If 3 out of 20 students live on campus, then the percentage of students who live on campus is 3/20 * 100 = 15%.

If there are 6000 students, then the number of students who live on campus is 15% of 6000 = 0.15 * 6000 = 900 students.