Q.1) Twelve (n) is the average number of calls arriving each minute at a certain calling center. The facilities at the calling center can handle at most 15 (m) calls per minute.

a) What is the probability that on a given minute customers receive a message "the line is busy"?

b) At a given minute, find the probability that the calling center waits more than 20 (t) seconds to receive new call

Q.2) Two hours (n) is the average interarrival times of oil tankers arriving each day at a certain port.

a) What is the probability that the port waits more than 5 (t) hours to receive new oil tanker?

b) If the facilities at the port can handle at most 15 (m) tankers per day. At a given day, find the probability that on a given day tankers have to be turned away.