An average of 2 calls arrives every 2 minutes. For a period of 0.1667 hour, what is the probability that 1. no calls arrive; (0.75 mark) 2. one call arrives; (0.75 mark) 3. two calls arrive and; (0.75 mark) 4. more than two calls arrive; and (0.75 mark) 5. If the average call duration is 2 minutes and a call lasted for 3 minutes, what is the probability that the call will last for at least another 3 minutes? (1 mark)