Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 20 passengers per minute.
a. Compute the probability of no arrivals in a 12-second period.
b. Compute the probability that five or fewer passengers arrive in a 30-second period.
c. Compute the probability of no arrivals in a 6-second period.
d. Compute the probability of at least one arrival in a 9-second period.