When someone buys a ticket for an airline flight, there is a 0.0995 probability that the person

Question:

When someone buys a ticket for an airline flight, there is a 0.0995 probability that the person will not show up for the flight (based on data from an IBM research paper by Lawrence, Hong, and Cherrier). The Beechcraft 1900C jet can seat 19 passengers. Is it wise to book 21 passengers for a flight on the Beechcraft 1900C? Explain.