3. For the transportation problem below, construct an initial feasible solution using the intuitive method. Dest. 2 18 COSTS Source 1 Source 2 Source 3 Demand Dest1 121 19 8 80 Dest 3 9 301 14 Dest 4 11 151 16 60 Supply 45 145 50 240 1240 10 30 701 Dest 1 Dest 2 Dest 3 Dest 4 Shipments Source 1 Source 2 Source 3 Supply 45 145 50 Demand 80 30 70 60 a. What is the cost of the intuitive method? b. What is the cost of the optimal solution (stepping stone method)? c. If Destination 1 required an increase of 10, what is the optimal cost? d. If Source 2 required a decrease of 40, what is the optimal cost