If $$1$$ out of $$6$$ lightbulbs is defective and there are $$2016$$ lightbulbs, how many of them are not defective? 
Overseas Competition->Knowledge Point->Word Problem Modules->Solving Problems Involving Fractions and Percentages->Knowing the Base
$$5$$ out of $$6$$ of the $$2016$$ lightbulbs are not defective. Thus $$2016 \times \frac{5}{6} =1680$$ lightbulbs are not defective. 