Answer:
Kindly check explanation as the question seems incomplete but the explanation should help.
Explanation:
Given the following :
Initial dosage of drug = 100mg
Halflife of drug = 6hours
After 18 hours, the percentage of drug that will be in the system should be :
Half-life is the time taken for a material to reduce to half of it's initial size.
Since half life = 6 hours
After 6 hours ; amount left = 100/2 = 50 mg
After 12 hours ; amount left = 50/2 = 25mg
After 18 hours ; amount left = 25/2 = 12.5mg
Hence, after 18 hours percentage left in system :
(Amount left / total initial amount) × 100%
(12.5 / 100) × 100%
0.125 × 100%
= 12.5%
