(a) Four companies. W, X, Y and Z supply the requirements of three warehouses. A, B and C respectively. The companies availability, warehouses requirements and the unit cost of transportation are given in the following table. Company W X Y Z Requirement A 10 (b) Least Cost Method 5 6 7 25 Warehouses B 8 2 7 6 26 (ii) Find an initial basic feasible solution using (a) North-West Corner Method C 9 3 4 9 49 Supply 15 20 30 35 (i) Construct a linear programming problem of this transportation problem and state why we cannot use Simplex method to solve it. 100 [10 marks] [5 marks] [5 marks] (c) Vogel Approximation Method (VAM) [8 marks] (d) Based on your answers from (ii)(a), (ii)(b) and (ii)(c), state which method(s) is better.