can someone explain this to me. step by step

The distribution system for the Herman Company consists of three plants, two warehouses, and four customers. Plant capacities and shipping costs per unit (in $) from each plant to each warehouse are shown below along with customer demand and shipping costs per unit (in $) from each warehouse to each customer. Plant 1 Plant 2 Plant 3 Warehouse 1 Warehouse 2 Plant Capacity 450 600 380 Customer 1 Customer 2 Customer 3 Customer4 Warehouse 1 Warehouse 2 Demand 300 300 300 400 Formulate the linear programming model to minimize the cost of shipping for this transshipment problem. A-at the optimal solution how much is shipped from Plant 3 to Warehouse 1? B-what is the range of optimality of coefficient of cost from Plant 3 to Warehouse 1 and what does this mean? C-what is the range of feasibility for the supply amount for Plant 2 and what does it mean? d-what is the range of feasibility for the demand amount for customer 2 and what does it mean