Considera tranisportation problem with three warchouse and four markets. The warehouse capacities are a-8, ay-10, ay-20. The markets demands are bi 6, bz=8, b;-9 and b-15. The unit cost of shipping is given in the following table: Solve by using two of the following methods and must be the third method of them. 1- North-west corner. 2- Minimum cell cost method. 3- Vogel's Approximation model. Ma My Ma W W2 W3 3. 3. 7. 4. 6. l00 4. (12 mark) 15 PA