Answer:
It is the portion of the cost based on renting a car for d days
Explanation:
Given:
Total cost = 15 + 18d
Total cost = fixed cost + variable cost
Fixed cost are cost that do not change.
Fixed cost = base rate = 15
Variable cost changes during production process. The variable cost in the above varies with the number of days (d)
Therefore, 18d is the portion of the cost based on renting a car for d days.
If you rent the car for 1 day
Total cost = 15 + 18d
= 15 + 18(1)
= 15 + 18
= 33