So, we need to make an equation.
Since it is depreciating at 20%, it will be 80% of what it previously was.
The equation will be
16,500×0.8^x=y
X will be replaced by 15, so we can find what it is.
16,500×.035184372088832
≈580.54
So, the value of the car in 15 years will be $580.54.