An airline, believing that 7% of passengers fail to show for flights, overbooks (sells more tickets than there are seats). Suppose that for a particular flight involving a jumbo-jet with 260 seats, the airline sells 280 tickets.
a. What is the expected number of ticket holders that will fail to show for the flight? i know this is 19.6
b. What is the probability that the airline will not have enough seats for all the ticket holders who show for the flight?