The question is meaningless. It uses "kilowatt" completely incorrectly.
"Watt" and "kilowatt" are rates at which energy is used, NOT
amounts of energy.
The question is a lot like saying that a car traveled for 5 hours at
4 miles per hour, so how many miles per hour did it travel each
hour it drove ?
======================================
If a machine used energy at the rate of 4 kilowatts when it's
running, then it uses 4 kilowatt-hours of energy during every
hour that it runs.
If it runs for 5 hours, then it uses
(4 kilowatts x 5 hours) = 20 kilowatt-hours
of energy during that time.
