premise: a light bulb is a kind of tool for seeing in the dark sent2: something that has a positive impact on something else is a kind of benefit sent3: if an object is discarded in a landfill then that object is trash sent4: to dispose of something can mean to discard something sent5: a light bulb is a kind of object sent6: humans move waste to a landfill for disposal / storage sent7: as the time a tool lasts increases , the number of tools discarded will decrease sent8: decreasing something negative has a positive impact on a thing sent9: landfills have a negative impact on the environment.
hypothesis: a benefit of increasing the time that a lightbulb lasts is  decrease in the amount of trash discarded in landfills