Answer:
378 patients
Explanation:
A doctor sees 126 patients in 3 days.
We can use this information to find how many patients he sees in one day.
126/3=42
The doctor sees 42 patients in 1 day.
Multiply that number by 9 to see how many patients he sees in 9 days.
42*9=378
The doctor sees 378 patients in 9 days.