Tasks on an assembly line are assigned to $2$ workstations as shown below. If the required cycle time is $100$ seconds, what is the idle time one unit incurs on the assembly line? $($slide $39)$

Workstation $1$

$\backslash$table$[[$Task$($s$)$ Assigned,Time $($sec$)],[$Task B$,30],[$Task E$,60]]$

Workstation $2$

Task$($s$)$ Assigned Time $($sec$)$

Task $10$

Task A $40$

Task $=20$