"The Debbie Dollar Income Tax Specialists are analyzing customer service operations during the month prior to the April filing deadline. On the basis of past data, it has been estimated that customers arrive according to a Poisson process with an average arrival rate of one every 12 minutes. The time to complete a return for a customer is exponentially distributed with a mean of 10 minutes. When the person is being helped, he meets with Debbie in her office. If the individual is waiting for help, he will be in the waiting area. Based on this information, answer the following questions.
Do not round your results to integer numbers.
a) If you went to Debbie, how much time should you allow for getting your return done? Measure this time from when you first arrive at her office.