Question

At $0.095/kWh, what does it cost to leave a 25W porch light on day and night for a year?

Answer 1

if you are charged $0.095 for each kW for each hour, you would be charged $0.095*25 = $2.375 for each hour your porch light is on... multiply that for the toatl hours in a year!

Answer 2

Please note that 25 watts = .025 kw, consider that in your solution.

Answer 3

as @radar said, i made a mistake, you will be charged $0.095*0.025=$0.002375 for each hour your porch light is on.