Compute the probability of no arrivals in a one-minute period (to 6 decimals)

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. The mean arrival rate is 7 passengers per minute

a. Compute the probability of no arrivals in a one-minute period (to 6 decimals)

b. Compute the probability that 3 or fewer passengers arrive in a one-minute period (to 4 decimals)

c. Compute the probability of no arrivals in a 15 second period (to 4 decimals)

d. Compute the probability of at least one arrival in a 15-second period (to 4 decimals)