What is the energy absorbed in each cycle and time?

Question

A particular engine has a power output of 5.00 kW and an efficiency of 20.0%. Assume the engine expels 6000 J of energy in each cycle.
(a) Find the energy absorbed in each cycle.

Your answer differs from the correct answer by 10% to 100%. kJ
(b) Find the time required to complete each cycle.
s

Answer 1

A watt is a Joule/sec. So the engine output is 5 kJ/s. "Your answer differs from the correct answer by 10% to 100%." It would have been helpful to know what you put in to get this response.

a) "Expels" ... does that mean wasted energy or useful energy? I'll assume it's useful energy. So 4 times as much energy is wasted - 24000 J.

b) 5 kJ/s * 1 cycle/6 kJ ==> 0.833 cycles/s or 1.2 s/cycle