Answer:
[tex]\boxed{\text{3600 mg}}[/tex]
Step-by-step explanation:
Step 1. Calculate the number of capsules
Marilyn takes 2 capsules per day
[tex]\text{No. of capsules} = \text{90 days} \times \dfrac{\text{2 capsules}}{\text{1 day}} = \text{ 180 capsules}[/tex]
Step 2. Convert capsules to milligrams
There are 20 mg in each capsule.
[tex]\text{No. of milligrams} = \text{180 capsules} \times \dfrac{\text{20 mg}}{\text{1 capsule}} = \textbf{3600 mg}\\\\\text{Marilyn will take } \boxed{\textbf{3600 mg}} \text{ of Pirixocam}[/tex]