The meaning of the question should be to fill a number in your mouth. If its score with 15 is three digits, how much can you fill in at most? If the product of it and 15 is four digits, how much can you fill in at least?

The first question: let's assume that the result is the largest three-digit 999, divided by 15, and the quotient is 66.6, then the answer to the first question is 66.

Second question: Let's assume that the result is the smallest four digits 1000, 100 divided by 15, and the quotient is 66.6666 ... Here, we should include decimal digits, because we want the smallest four digits. So the second question is answer 67.

You can check 67X 15= 1005.