Operation management

A campus deli serves 250 customers over its busy lunch period from 11:30 am to 1:30 pm. A quick count of the number of customers waiting in line and being served by the sandwich makers shows that an average of 15 customers are in process at any point in time. What is the average amount of time that a customer spends in process? Instruction: Round your intermediate and final answer to 1 decimal place. Average amount of time 12.0 minutes (Round to one decimal)