Question

The cars access code has four digits first digit cannot be zero and the last digit must be even

Answer 1

There's 9 choices for the first digit and 4 choices for the last digit. The number of choices for the 2nd and 3rd digits is 90 if 2 numbers are different. or 100 if duplicates are allowed.

If duplicates are allowed the answer is 9 * 100 * 4 = 3600 possible numbers.