Answer:
Part 1) The cost per second is

Part 2) The cost per customer is

Explanation:
Part 1) Calculate the cost per second
we know that
To find out the cost per second, divide the total cost by the time
Let
x ----> the total cost
y ----> the time in seconds
we have



therefore
The cost per second is

Part 2) Calculate the cost per customer
we know that
To find out the cost per customer, divide the total cost by the number of customers
Let
x ----> the total cost
y ----> the number of customers
we have



therefore
The cost per customer is
