ANSWER :
27.44 mg
EXPLANATION :
From the problem, we have the function :
where I = initial amount
e = euler's constant
r = rate
t = time
We have :
I = 50 mg
r = -10% or 0.10 (Negative because this amount leaves the bloodstream)
t = 6 hours
The amount of medicine after 6 hours is :
The answer is 27.44 mg