Transportation Example

Demand Total Supply at Node S$\_$i

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

Sources S$113756300$

S$21210411150$

S$341489200$

Total demand at node D$\_$i $90120150280$

Table $1$: Costs and Constraints

In the given table, you see the costs and the supply and demand constraints. What is the required supply at node D$2?$