Widget & Co. wants to open a number of stores in different cities. Since a store in a city can serve nearby cities to some degree Widget & Co. wonders if they can open stores in only some cities. They want to minimize the total cost of opening stores but cover 100% of the population. A sore covers that opens in a city covers 100% of the population in that city and 25% of the population in a nearby city. If a city have four stores opened in nearby cities 100% of the population in that city is covered. If a store is opened in a nearby city, 25% of the population goes to that store. If stores in two nearby cities are opened 25% of the population goes to one of the stores and 25% goes to another for a total of 50%. If stores are opened in four nearby cities 100% of the population in the city goes to a store and if more than four stores are opened in nearby cities no more than 100% of the population goes to a store. The cost of open a store and what cities are nearby can be read of in the table below. City Nearby cities Cost A LN 30410 BKDGH 36582 CIME 30444 D BEGHK 49379 E DKH 31960 F CM 31383 GBDHIK 41887 HBDEGK 47951 I CGMO 42472 JIMO 39737 LAN 29764 K BDEGH 46729 M ICF 40912 NAL 34174 OT 33645 Formulate a binary model helping Widget & Co. to decide in which cities to open stores so that 100% of the population goes to at least one store and the total cost of opening stores are minimized. (6p)