How many pounds of carbon dioxide would you prevent from entering the atmosphere in one year, if you were to replace a 100-watt light bulb with a CFL bulb that uses 32 watts in a fixture that you have on 3 hours per day?

Answer: 73.596 pounds

Step-by-step explanation:

We know that a kWh is related to emissions of 0.9884 lbs.

Then for the 100-watt light bulb we have.

It is used 3 hours per day, so it consumes 3*100 = 300 Wh

and 1 kWh = 1000 Wh, so 300wh = 0.3 kWh.

Then, in one day, this light bulb produces:

0.3*0.9884 lbs = 0.297 lbs of carbon dioxide.

In one year, it produces:

365*0.297 lb = 108.230 lb

The 32 what light bulb is also used 3 hours per day:

3h*32W = 96 Wh or 0.096 kWh.

In a day, this light bulb produces:

0.096*0.9884 = 0.095 lb of carbon dioxide.

In a year, it produces:

365*0.095 lb = 34.633 lb.

The difference in the year production is:

D = 108.230 lb - 34.633 lb = 73.596 lb.

This means that using the 32 watts bulb prevents, in a year, 73.596 pounds of carbon dioxide to enter in the atmosphere.