Answer :
Cost savings in using the fluorescent bulb is 3.81 cents
Explanation:
A 100 watt incandescent light bulb is operated for 7 hours.
Energy used by 100 watt incandescent light bulb = Power x Time
Energy used by 100 watt incandescent light bulb = 100 x 7 = 700 Wh
Energy used by 100 watt incandescent light bulb = 0.7 kWh
A 32 watt fluorescent light bulb is operated for 7 hours.
Energy used by 32 watt fluorescent light bulb = Power x Time
Energy used by 32 watt fluorescent light bulb = 32 x 7 = 224 Wh
Energy used by 32 watt fluorescent light bulb = 0.224 kWh
Cost of electricity per kWh = 8 cents
Cost of electricity by 100 watt incandescent light bulb = 0.7 x 8 = 5.6 cents
Cost of electricity by 32 watt fluorescent light bulb = 0.224 x 8 = 1.792 cents
Difference in costs = 5.6 - 1.792 = 3.808 cents
Cost savings in using the fluorescent bulb is 3.81 cents