help me please!

Question 7 (4 points) In a small town, 6 retailers (R1 to R6) buy juice from a local factory (F). The factory is responsible for the transportation of the juice, and it owns 5 warehouses (W, to Ws) to store the juice. All juice is first transported from the factory to a warehouse and then delivered to the retailer. The annual demand of each retailer (ton) is listed in the following table. Retailer R1 R2 R3 RA RS R6 Demand 200 345 260 180 220 205 The factory has to pay a fixed maintenance cost to operate each warehouse. In order to decrease the total cost, the factory decides to shut down some of the warehouses. The annual maintenance cost (USD/year) of each warehouse, the capacity (ton) (i.e., the maximum amount of juice that can be transported from the factory) of each warehouse, the unit transportation cost (USD/ton) from the factory to each warehouse, and the unit transportation cost (USD/ton) from each warehouse to each retailer are listed in the following table. W 5500 W, 2900 350 4 W 3000 370 Ws 8000 500 600 3 6 5 3.5 1 2 4.5 3 25 2020/21, Som Warehouse W Maintenance cost 5000 Capacity 400 Unit 5 transportation cost from F Unit 2.5 transportation cost to R Unit 3 transportation cost to R2 Unit 3 transportation cost to R Unit 2 transportation cost to R Unit 3 transportation cost to Rs Unit 2 transportation cost to R6 3 2 2.5 3 2 2 3 4 4.5 3 3 2 1.5 3 3 2 3 2 4 And for each retailer, it can get delivery from more than one warehouse. The factory aims to minimize the annual total costs while making sure that all demands from retailers should be fulfilled. Please formulate an LP or IP or MIP model that can be used to determine which warehouse(s) should be shut down and how should the juice be transported after the warehouse(s) is shut down. Hints (note that the following is just one option of formulating the model, there may be many correct ways to formulate the model): The decision variables are: 1. Xi, binary variable, equal to 1 if W is kept and Oif W is shut down; i = 1,...,5 2. qij the quantity (ton) of juice that R; receives from W; i = 1, ...5;j = 1,...,6 3. y, the quantity (ton) of juice transported from the factory to W., i = 1,...,5