Question

The number of 'three-digit numbers' that can be formed using the digits from 1 to 9 without the repetition of each digit is \(\underline{\hspace{2cm}}\).

Hint:

For counting problems with no repetition, multiply the number of choices for each digit.

Answer 1

Correct Answer: 504

To form a three-digit number using the digits from 1 to 9 without repetition, we have:
- 9 choices for the first digit (since it can be any number from 1 to 9),
- 8 choices for the second digit (since repetition is not allowed),
- 7 choices for the third digit.
Thus, the total number of three-digit numbers is: \[ 9 \times 8 \times 7 = 504. \] So, the total number of three-digit numbers is 504.