A new shopping mall is considering setting up an information desk staffed by one (1) employee. Based upon information obtained from similar information desks, it is believed that people will arrive at the desk at the rate of fifteen (15) per hour. It takes an average of two (2) minutes to answer a question. It is assumed that arrivals are poisson-distributed and that answer times are negative-exponentially-distributed.

REQUIREMENT:

1. Find the proportion of the time that the employee will be busy.
2. Find the average number of people just waiting in line to get some information.
3. Find the expected time a person will spend just waiting in line to have his/her question(s) answered.