Because 10% of the reservation holders are no-shows, a U.S. airline sells 400 tickets for a flight

Question:

Because 10% of the reservation holders are "no-shows," a U.S. airline sells 400 tickets for a flight that can accommodate 370 passengers.
(a) Find the approximate probability that one or more reservation holders will not be accommodated on the flight.
(b) Find the approximate probability of fewer than 350 passengers on the flight.