One tablet contains 150 mg of the active ingredient. Then, 90 tablets contain
[tex]90\text{ tablets }\cdot\frac{150\text{ mg}}{1\text{ tablet}}=13500mg_{}[/tex]1 gram is equivalent to 1,000 mg, then 13500 mg is equivalent to
[tex]13500\text{ mg}\cdot\frac{1\text{ gram}}{1000\text{ mg}}=13.5\text{ grams}[/tex]There are 13.5 grams of the active ingredient in the entire bottle