Answer:
Customer have to drive for 100 miles for the cost to be $140.
Explanation:
Here, the cost of rest function is given as:
C = 120+.20 m
From above function, we can see that :
m = Number of miles traveled by the rent car
(1) The fixed rental charge of renting a car = $120
(2) The per mile rent of the car = $0.20
Now, C = $140
⇒140 = 120+.20 m
or 140 - 120 = 0.20 m
or, 0.20 m = 20
⇒ m = 20/0.20 = 100
or, m = 100
Hence, customer have to drive for 100 miles for the cost to be $140.