A university admits 300 freshmen per year. The university offers a four-year program. They have a policy to never fail students, so all students eventually graduate. Each student is a freshman, sophomore, junior or senior. If students never repeated a semester, there would be 300 students in each classification and every student would graduate in four years. Students do repeat semesters as many times as necessary to earn a passing grade so there are generally more than 300 in each classification and the average student takes longer than four years.

How long does the average student take to complete his or her education?