Determine an initial basic feasible solution to the following

transportation problem by using

a$)$ the least cost method; $[1]$

b$)$ Vogel$$s approximation method. $[1]$

Destination $($Di$,$ i$=1,2,3,4),$ Source $($A$,$ B$,$ C$)$

D$1$ D$2$ D$3$ D$4$ Supply

A $11131714250$

B $16181410300$

C $21241310400$

Demand $200225275250$