Airlines like to overbook their flights (this is a vibrant area of research called yield management). It is estimated that 10% of the people who book their flight do not show up.
Hint: Define X = number of people who show up for the flight
a. If a small plane holds 20 people, compute the probability that there will not be enough seats for all the booked passengers, if the airline books B people, where B = 19,20, 21, 22.
b. If there are 10 identical small plane flights, each booked to 22, then find the probability that zero or one flights are overbooked?