an international air carrier plans to purchase a jumbo-class air craft to serve the chicago-london city pair .restrictions in landing slots at heathrow airport allowed the purchase of five landing/take-off slots , one per week day . the carrier does not intend to offer weekend service .the following table presents passenger demand estimates anf fares charged by competitors :

trip	five-weekday demand	one-way fare ($)
chicago-london-chicago	975	400
chicago-london	230	680
london-chicago-london	880	475
london-chicago	400	775

the round trip chicago-london-chicago is 13,000 km , and the air craft choises and costs are :

aircraft	seating capicity	oper.cost seat-km	fixed cost/year
B-747	385	2.75 cent	$4.5 million
DC-10	235	2.97 cent	$3.7 million

should the airline enact service and which aircraft should be chosen? solve based on profit maximization .

Whether chicago - london people re subset of the people who have confirmed for the return ticket. And same case with the london - chicago? yes i think ,solve it like if it's or it's not