Q$.4$ There are three sources and three distribution centers. The supply limit$,$ dermand amount and the unit tuansportation costs are given in the following table:

$\backslash$table$[[$From:$,$D:$,$E$,$F$,$Supply$],[$A$,6,4,1,50],[$B$,3,8,7,40],[$C$,4,4,2,60],[$Demand$,20,95,35,]]$

$($i$)$ Formulate mathematical model.

$($i$)$ Use North Wert Comer Method to find the initial basic feasible solution.

$($ii$)$ Find optimal solution by Simplex Transportation method or MODI method.