1. The problem statement, all variables and given/known data
A certain power supply provides a continuous 371W to a load. It is opperating at 0.13% efficiency. In a 129 day period, how much does it cost (in dollars) to run the device if electricity costs 0.34 $ per kWh?
2. Relevant equations
im not sure..... everything has to be to 3 significant digits after the decimal.
3. The attempt at a solution
i have tried this a few different ways.... im not sure where the efficiency comes in.
this is what i did:
129days x 24= 3096hours
.371kW x 3096= 1.4932008kWh
1.4932008kWh x .34 = .507688272
answer is: $0.508