The assembly line for a music system of cars has the activities as mentioned in the table below for a demand of $120$ systems per day with $8$ hours of production time per day. You are supposed to determine

a$.$ Draw the precedence graph.

b$.$ What is the cycle time?

c$.$ Theoretically, how many number of workstations are required? $[1$ mark$]$

d$.$ Assign the tasks to the workstations?

e$.$ Based on the number of workstations in $($d$),$ what is the efficiency and the idle time?

$\backslash$table$[[$Tasks$,\backslash$table$[[$Task Time$],[($Seconds$)]],\backslash$table$[[$Task must$],[$follow$],[$listed below$]]],[$A$,90,-],[$B$,155,-],[$C$,140,$A$,$ B$],[$D$,120,$C$],[$E$,180,$B$],[$F$,90,$E$],[$G$,160,D,F$