A patient is given a 50 mg dose of medicine. The medicine's effectiveness decreases every hour at a constant rate of 40%. What is the exponential decay function that models this scenario? How much medicine will be left in the patient's system after 2 hours?

It should be noted that only 60% of the medicine of the previous hour is left n the patient's system every hour. Thus, the model of the scenario is,

D = 50 mg (0.6^n)

where D is the dosage at any hour n.

Using the model above with n equal to 2. D becomes 18. Therefore, only 18 mg is left in the patient's system after 2 hours.