Soon After Taking an Aspirin, a Patient Has Absorbed 310

Multiple Choice

Soon after taking an aspirin, a patient has absorbed 310 mg of the drug. If the amount of aspirin in the bloodstream decays exponentially with half being removed every 2 hours, find the amount of aspirin in the bloodstream after 9 hours. ​
Select the correct answer.
​

A) 1,370
B) 137
C) 50
D) 13.7
E) 2.21