Answer:54 secs
Step-by-step explanation:
Task Time(secs) Immediate Predecessor
u 30 none
v 30 u
w 6 u
x 12 w
y 54 x
z 30 v,y
The minimum possible cycle time is defined as length of longest task time from the number of tasks required to produce a product.
From the table given above culled from the question, 54seconds is the length of the longest task time.