An airline sells all the tickets for a certain route at the same price. If it charges 200 dollars per ticket it sells 10,000 tickets.

An airline sells all the tickets for a certain route at the same price. If it charges 200 dollars per ticket it sells 10,000 tickets. For every 30 dollars the ticket price is reduced, an extra thousand tickets are sold. Thus if the tickets are sold for 170 dollars each then 11,000 tickets sell. It costs the airline 100 dollars to fly a person.(a) Express the total profit P in terms of the number n of tickets so