Hi, I have a question for which the answer is provided but I don't know how it is derived, could you help to explain it step by step please?

Thank you in advance!

In Problem 6, suppose that two Cournot duopolists serve the Peoria-Dubuque route, and the demand curve for tickets per day is Q = 160 - 2p (so p = 80 - Q/2). Total costs of running a flight on this route are 400 + 20q, where q is the number of passengers on the flight. Each flight has a capacity of 80 passengers. In Cournot equilibrium, each duopolist will run one flight per day and will make a daily profit of Correct! $400. $1,600. O $160. O $800 O $200