An Energy Efficient Light Bulb Uses 15 W of Power

Multiple Choice

An energy efficient light bulb uses 15 W of power for an equivalent light output of a 60 W incandescent light bulb.How much energy is saved each month by using the energy efficient light bulb instead of the incandescent light bulb for 4 hours a day? Assume that there are 30 days in one month.

A) 5.4 kW.hr
B) 1.35 kW.hr
C) 21.6 kW.hr
D) 1.8 kW.hr
E) 7.2 kW.hr