You are offered a zero percent finance offer for a new car purchase as a graduating senior .

You select a car and the dealership informs you that in view of your excellent credit You can buy this car with zero down and zero interest for 60 months at $550 per month.

However, you run an internet search and the same car is being offered for $30,000 in cash.

What is the APR being charged by the dealership offering you a zero interest in %