I am going to call your teacher out on the question. I feel it is lacking vital information. Specifically whether the voltage is AC or DC. If it is DC, then all is fine and well, but based upon the numbers, it is very similar to an AC circuit, so I would imagine the circuit in question is AC. As such, you need to know if the voltage you are given is RMS or the amplitude. If it is just the amplitude then you must divide by 2^.5 and you will get a power of 2546 W. Also, if you wan't to actually know the answer, you must know the nature of the load. If it has inductors/capacitors, then the power factor is likely less than 1. This means there is a phase angle difference between the voltage and the current, consequentally the apparent power is greater than the real power, which means less 'real power' is available at the load.
So, your teacher failed to provide you with several vital peices of information, and consequentally it is impossible to know the correct answer (Though it is very likely 3600W).
