Jack Weatherhead is a first-year MBA student. In order to pay the rent, he decides to take the job in the computer department of a local department store. His only responsibility is to answer phone calls from customers about store hours and product availability. As Jack is the only person answering the calls, the manager of the store is concerned about queueing problems. Currently, the department receives a call every 3 mins on average. The standard deviation of the inter-arrival time is 3 mins. Jack can handle a call in 2 mins on average, with a standard deviation of 1 min. The customer service number is toll-free. For each incoming call, the store has to pay the phone company at a price of $5.00 per hour, regardless of whether the call is being answered or is waiting. Assume that the customers do not hang up even if having to wait for a long time. Jack has to answer a phone call. He can answer 1 phone call per 2 minute. How many calls Jack can take?