$(3$ points$)$ This is a Transportation Problem. A furniture company owns three warehouses $($call

them $1,2,$ and $3).$ It needs to deliver tables to its four shops $($call them $A,B,C,$ and $D).$ The

four shops demand the following:

Shop A needs $45$ units.

Shop $B$ needs $30$ units.

Shop $C$ needs $40$ units.

Shop $D$ needs $40$ units.

Current stock level of chairs in the warehouses is as follows:

Warehouse $1$ has $45$ units.

Warehouse $2$ has $60$ units.

Warehouse $3$ has $50$ units.