Determine the optional solution

Nash Auto has two plants (node numbers 1 and 2), two warehouses (node numbers 3 and 4), and two customers (node numbers 5 and 6). Cars are produced at plants, then shipped to warehouses, and finally shipped to customers. Plant 1 produces 100 cars per week, and Plant 2 produces 200 cars per week. Customer 1 (node number 5) requires 250 cars per week, and customer 2 (node number 6) needs 150 cars. The costs of shipping a car between nodes are listed in the Table. 4 5 6 From 1 2 3 3 $10 $5 $6 $7 $8 $9 $18 $12 4 $11