Approaching this question, I first calculated the TOTAL cost of the trip (that is, $D(v) + F(v))$. This gave me $\dfrac{1}{v} (5v^{\frac 5 2} + 2059V + 150 000)$.
Am I right in saying I now have to calculate this cost in cents per km? And would I do this by dividing the cost (in cents per trip) by $v$?