The question can be interpreted in two ways: how many three-digit numbers are there from 100 to 999 (inclusive), or how many three-digit numbers are there from 100 to 1000 (inclusive). We will address both.
Interpretation 1: Three-Digit Numbers from 100 to 999 (Inclusive)
The reference states: "Before we see the list of three digits numbers, first let us discuss how many three digits numbers we have from 100 to 999. Hence, there are 900 three-digit numbers in total."
Therefore, there are 900 three-digit numbers from 100 to 999 (inclusive).
Interpretation 2: Three-Digit Numbers from 100 to 1000 (Inclusive)
Since 1000 is a four-digit number, the three-digit numbers between 100 and 1000 are the same as those between 100 and 999. However, if the question specifically asks to include 1000 within the range, this interpretation is slightly different. The range is 100 to 1000 inclusive. Since we're asked how many three-digit numbers fall in this range, only the numbers 100 through 999 are relevant. 1000 is a four-digit number.
The answer remains 900 because the number 1000 does not fall in the category of three-digit numbers.
