I will do step by step:
A) First we have to find the total cost considering that it will take one week as the question says "You rent an 8-passenger van for a week". They will travel 2480 miles in total (round-trip). Thus:
"The rate is $399.00 a week with 1.500 free miles and 80.25 per additional mile." Mathematically this means:

Obs: The additional miles are (2480-1500).
The CDW fee is $165.00 for the week, and the estimated gasoline cost is $600.00. It is one week, so we can add it into the total cost formula:

Making the calculations, the total cost will be:

B) The full course is 2480 miles, so to find the round-trip per mile we can divide them:

C) Per person is the same reasoning:
