Final answer:
A patient uses 12 puffs of their inhaler per day (2 puffs every 4 hours), so a 200 puff inhaler would last for 16.67 days, which means it would fully last for 16 days.
Step-by-step explanation:
To calculate how many days the inhaler with a total of 200 puffs will last, we must first determine the number of puffs the patient uses per day. The patient takes 2 puffs every 4 hours. There are 24 hours in a day, so the patient would use the inhaler 6 times a day (24 ÷ 4 = 6). This means the patient uses 12 puffs per day (2 puffs × 6 times a day).
Next, we divide the total number of puffs in the inhaler by the number of puffs used per day to find out how many days the inhaler will last: 200 puffs ÷ 12 puffs per day = 16.67 days. Since a patient can't use a fraction of a day's worth of medication, the inhaler would last for 16 full days.
Therefore, the answer is (b) 16 days.