Ken has five 200W security lights on outside of home. How much energy do the security lights use in 8 hrs?
If the cost of electricity is 8 cents per kWh,what is the cost of operating the security lights ?
Please help I'm not sure which formula to use?
5*200 = 1,000 watts = 1 kw
1 * 8 = 8 kw hr
8 cents/kw h * 8 kw h = 64 cents every 8 hours