An assembly

$-$

line process has six tasks, as listed in the table below: Task time Task

$115$

$$min Task

$28$

$$min Task

$317$

$$min Task

$420$

$$min Task

$56$

$$min Task

$624$

$$min Four workers

$($

S

$1$

$,$

$$S

$2$

$,$

$$S

$3$

$,$

$$and S

$4)$

$$are staffed to this assembly line, and the assignment of tasks to each worker is as follows:

$$

$$S

$1$

$$does Task

$1$

$.$

$$

$$S

$2$

$$does Tasks

$2$

$$and

$3$

$.$

$$

$$S

$3$

$$does Tasks

$4$

$.$

$$

$$S

$4$

$$does Tasks

$5$

$$and

$6$

$.$

$$For the following questions, we assume that the process is operating at full capacity.