Quote by cepheid
0.13% = 0.0013
This is the ratio of output power to input power:
P_out / P_in = 0.0013
Hence, P_in = P_out / 0.0013
This result makes sense since it means the input power is much greater than the output power (due to the inefficiency in the supply). Once you have P_in, you can just do the same calculations as before. I was hoping that you would write these equations down and work it out for yourself. They are nothing more than the mathematical version of what I said in post #5 using words.

i actually did write them out...but i used multiplication instead of division. this is only my second week of class, and i have been out of school for a decade. i know this question probably isnt a hard one, but its 1:43am here and my brain hurts from 4 hours of homework. i really do appreciate the help!