An 80 watt incandescent light bulb is operated for 15 hours, and a 15 watt fluorescent light bulb is operated for the same period of time. At 10 cents per kWh, what is the cost savings in using the fluorescent bulb?

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