3. How many six-digit numbers can be created using the digits 1, 2, 3, 4, 5, 6?

There are 6 choices for the first digit, then 5, 4, 3, 2, and 1 choices for the remaining positions, since digits cannot be repeated.

\(6\cdot5\cdot4\cdot3\cdot2\cdot1=720\)

Answer: 720