Answer:
Number of vats used is 3
Step-by-step explanation:
Number of pounds used per hour, D = 195 ÷ 8
= 24.375 pounds per hour
Cycle time, T = 2.25
Inefficiency factor, e = 0.19
Material held in vats, C = 25 pounds
Now,
Let, n be total number of vats
Thus,
n =

on substituting the respective values, we get
n =

or
n = 2.413 ≈ 3
Number of vats used is 3 [since vats cannot be in fraction]