Answer
0.01 kg of Lipitor per 100 pills.
Work Step by Step
each bill weights 2.5 grams and has exactly 4% of the active ingredient. thus, each pill has:
2.5 grams $\times$ $(4\div100)$ = 0.1 grams of Lipitor.
Therefore, 100 pills contains $(100 \times 0.1 grams)$ = 10 grams/100 pills.
to convert into kilograms as the questions asks: $ 10 grams \times \frac{1 kg}{1000 grams} = 0.01 kg$
