Answer
Maximum cars = 200 cars
This relates to the law of definite proportions because, similarly to a compound that always contains the same proportion of elements, a car will contain the same proportion of wheels and body.
Procedure
To solve this problem, we will consider that a car needs 1 body and 4 wheels and that you can produce cars as long as you aren't missing the body or a wheel.
We divide 900/4 = 225 sets of wheels
The limiting part will be the bodies. Therefore you can only produce 200 cars. This relates to the law of definite proportions, which states that a given chemical compound contains the same elements in the same proportions by mass. For example, pure water contains 11.19% hydrogen and 88.81% oxygen by mass. It does not matter where the sample of water came from or how it was prepared. Similarly, any car contains a body and 4 wheels.