Solve the following transportation problem using any suitable method and state the minimum expected cost of transportation

$(13$ marks$)$

Construction Site S$1$ S$2$

W$1$

$8|$

Supply $120$l

Factory

W$2$

$15$

$10$

$10$

$80$

W$3$

$80$

$3$

Demand

$150$

$70$

$6$f

$280$