Answer:
Step-by-step explanation:
An 80 watt incandescent light bulb is operated for 15 hours. This means that the number of watt hour hours used is 80×15 = 1200 kilo watt hour.
A 15 watt fluorescent light bulb is operated for the same period of time. This means that the number of watt hour hours used is 15 ×15 = 225 kilo watt hour.
At 10 cents per kWh, the total cost of 1200 kilo watt hour would be 1200×10 = 12000 cents = $120
At 10 cents per kWh, the total cost of 225 kilo watt hour would be 225×10 = 2250 cents = $22.5
The cost savings in using the fluorescent bulb would be 120 - 22.5 =$ 97.5