When a certain positive integer P is divided by 7, the remainder is 3. What is the remainder when 3P is divided by 7?

✓ Correct Answer: Option B

If P divided by 7 has a remainder of 3, P can be expressed as 7k + 3. Then 3P = 3(7k + 3) = 21k + 9. When 21k + 9 is divided by 7, 21k is perfectly divisible. The remainder comes from 9 divided by 7, which is 2.