The local drivers license center processes applications for drivers license renewals through the following three steps. First, the customer registers with the receptionist, who updates the customers information in the database. This first step takes 2 minutes per customer. Then, the customer visits one of 1 cashiers to pay the associated fees for the license renewal. This takes 4 minutes per customer because several forms must be printed from the computer and signed by the customer. Finally, the customer visits one of 3 license processing stations where the customers picture is taken and the license is printed. This final step takes 13 minutes per customer.

If the system starts empty and operates worker paced, how long does it take to complete the processing of 7 customers?