The first digit can only range from 1-9, resulting in 9 possible options. The last digit can only be 2, 4, 6, and 8, resulting in 4 possible options. The other four digits can range from 0-9, resulting in ten options for each. Using the fundamental counting principle, we can use the following equation to solve for the different amount of codes possible.
[tex]9 \times 10 \times 10 \times 10 \times 10 \times 4 \\ 360000[/tex]
