Stanford Rosenberg Computing wants to establish an assembly line for producing a new product, the Personal Digital Assistant $($PDA$).$ The tasks, task times, and immediate predecessors for the tasks are as follows:

TASK TIME $($sec$)$ IMMEDIATE PREDECESSORS

A $12$

B $15$ A

C $8$ A

D $5$ B$,$ C

E $20$ D

Rosenberg$$s goal is to produce $180$ PDAs per hour. What is the cycle time? What is the theoretical minimum for the number of workstations