Answer:
50 estimate
47.9 accurate amount.
Explanation:
If the question says estimate, then that's what you have to do -- estimate. That means you put your calculator in a drawer and NO cheating.
Suppose that the total is 450. You've only added 19 cars to the total. That's not very much -- just two cars per lot more (about)
450/9 = 50 because 45/9 = 5
So each lot has about 50 cars in it. HMM. Just how close is that? Now and only now you get to check it out. My calculator tells me it is 47.9 which is out by very little really.