So the equation When I have a total of N cars of same model in my agency would be ,
N( vehicle cost - Resale value + maintenance & repair cost) +Business overhead = Rate per day * no. of rental days.
Is there any other factors that I could have possibly missed?
I am planning to sell car in 2yrs or 100000 KMS whichever comes first....
Two problems. One of which makes the problem
AS POSED insoluble. I shall give you a solution as soon as you tell me what the business overhead is in money for 100,000 km. You can put a number on business overhead for a year or two years, but not on 100,000 km because the whole idea of business overhead is that it varies with time but not the volume of business.
A second problem, and the one that cannot be answered with free advice from the internet, is this. The number of rental days that you can reasonably expect
per car is dependent on how many cars you have in inventory.
If you ignore both problems, a reasonable solution is this:
Let n = break even number of cars, p = purchase price per car, s = sale's price in second hand market per car, i = insurance cost per car for two years, m = maintenance cost per car for two years, b = business overhead for two years, r = rate per day rented, and d = number of days a car is rented over two years.
\(\displaystyle If\ (r * d) > (i + m + p - s) \implies n * r * d - \{b + (n * \{i + m + (p - s)\})\} = 0 \implies n = \dfrac{b}{(r * d) + s - i - m - p}.\)
However, ignoring the issue that the number of rental days per car is almost certainly dependent on the number of cars in inventory means that the formula above will almost certainly generate a number that is too high, perhaps way too high. That is, if you use that formula, you will end up with a lot of seldom-used cars mostly sitting on the lot. If this were a consulting gig for me, it is working on this part of the process that would justify my outrageous fees.