You can put this solution on YOUR website!
I think I might have found a solution for you.
I'm not sure if you're familiar with PERT,
but it's a very useful model for computing population growth over time. In this case, we can use it to model the growth of motor vehicles over time.
So for this little problem, I came up with
We set this up by knowing that in
, P is the principle (or the population where time is zero), r is rate, and t is time.
If you choose values for time and plug this into your calculator, you shouold come up with pretty accurate answers.