How much money would you save per hour by replacing a 100-watt incandescent light bulb with an equally bright 20-watt fluorescent bulb? Assume the cost for electricity to be 15 cents per kilowatt-hour.
A)1.5 cents per hour
B)1.2 cents per hour
C)0.3 cent per hour
D)It's not possible to save only a fraction of a cent.

Question

Quizplus · Accepted Answer

To calculate the hourly savings, we need to find the difference in energy consumption between the two bulbs. 
100 watts is equivalent to 0.1 kilowatts (since 1 kilowatt = 1000 watts). 
20 watts is equivalent to 0.02 kilowatts. 
So, the hourly savings would be: 
0.1 kilowatt - 0.02 kilowatts = 0.08 kilowatts 
To find the cost of 0.08 kilowatts, we multiply it by the cost of electricity per kilowatt-hour: 
0.08 kilowatts x 15 cents/kilowatt-hour = 1.2 cents
Therefore, the answer is B which means that you would save 1.2 cents per hour by replacing the incandescent bulb with a fluorescent one.

How Much Money Would You Save Per Hour by Replacing