Answer:
[tex]A=50(0.6)^x[/tex]
18 mg of medicine will be left in the patient's system after two hours.
Step-by-step explanation:
Given,
The initial quantity of the medicine, P = 50 mg,
Also, it decreases every hour at a constant rate of 40%
That is, r = 40 %,
Thus, the quantity of the medicine after x hours,
[tex]A=P(1-\frac{r}{100})^r[/tex]
[tex]=50(1-\frac{40}{100})^x[/tex]
[tex]=50(1-0.4)^x[/tex]
[tex]=50(0.6)^x[/tex]
Which is the required exponential decay function that models this scenario.
The quantity of the medicine after 2 hours,
[tex]A=50(0.6)^2=18\text{ mg}[/tex]