An airline has two types of passengers:

A. If the airline can charge only one price to all passengers and its marginal cost of supplying a seat on a flight is $300, the airline will sell (????) seats and charge a price of $(???????) for each seat.

B. 

. If the airline can charge different prices to the two different types of passengers and its marginal cost of supplying a seat is still $300 per seat, then business travelers will buy  (???????) seats at a price of (?????????)$ per seat and vacation travelers will buy  (???????) seats at a price of (????????)$ per seat.