At а typicаl drive-thru custоmers stаrt by cоnsulting a billbоard and placing an order with an employee (via intercom). The customers do not wait for the order to be produced, but proceed directly down the line to pay at the cash register. While customers pay the kitchen staff prepares the order. Finally, (after the payment is completed) the meal is collected at the last window. Placing an order takes on average 60 seconds. Preparing the meal requires 120 seconds. Paying at the cash register requires 50 seconds. Collecting the prepared meal requires 10 seconds. What is the theoretical flow time of the process?