1) we calculate the volume of the first carton:
volume=length x width x height
volume=3 ft * 2 ft * 2 ft=12 ft³
Therefore:
A machine can fill 12 ft³ in 3 seconds.
2) we calculate the volume of the second carton.
volume=length x width x heigth
volume=4 ft * 5 ft * 6 ft=120 ft³
3) we calculate the time that the machine needs for fill the second carton with packing material by the rule of three.
12 ft³---------------------3 seconds
120 ft³-------------------- x
x=(120 ft³ * 3 seconds) / 12 ft³=30 seconds.
answer: 30 seconds.