Duffin house is about to start a promotional blitz for its new book, physics for the liberal arts. the company has 10 salespeople stationed in chicago and 20 in denver, and it would like to fly 15 of them to sales fairs at each of los angeles and new york. a round-trip plane flight from chicago to la costs $200; from chicago to ny costs $150; from denver to la costs $400; and from denver to ny costs $200. for tax reasons, duffin house needs to budget exactly $7,750 for the total cost of the plane flights. how many salespeople should the company fly from each of chicago and denver to each of la and ny?