Depends on how many cars your talking about.Be more descriptive.
Answer:
A. Twice the radius, d = 2r
Step-by-step explanation:
The diameter is a line that splits a circle in half, while the radius is only half of that.
For this case we have the following equation:

Let 
We have:

By definition, given an equation of the form 
The quadratic formula, to find the solution can be written as:

In this case we have:

Substituting in the quadratic formula we have:
See attached image
Answer:
Option B
8.57 for the first one and, I’m not sure a bout the second time though
Answer:
Subtract 60 from the sum of 8e and 20 when e=7
8e +20
8(7) + 20
56+20=76
76-60=16