The kinetic theory of gases is a simple, historically significant model of the thermodynamic behavior of gases, with which many principal concepts of thermodynamics were established. The model describes a gas as a large number of identical submicroscopic particles, all of which are in constant, rapid, random motion
Power = Work / time
The work given here is 83J and the time it took to do 83J of work was 3s
So..
Power = 83J / 3s
Power = 27.67 W or 27.7 W