Alfredo deDarke sleeps with a 7.5-Watt night light bulb on. He turns it on before getting in bed and turns it off 8 hours later.
a. Determine the amount of energy used during one evening in units of kiloWatt*hours.
b. Electrical energy costs 13 cents/kW*hr where Alfredo lives. Determine the annual (365 days) cost of this practice of using a 7.5-Watt night light.
c. Determine the annual savings if Alfredo replaced his 7.5-Watt incandescent night light by a 0.5-Watt LED night light.