The code of five digits is of the form:
A B C D F
Where A (the first digit) may be any of 9 digits (because 0 is excluded)
B, C, and D, may be each any of 10 digits (0 - 9)
F (the last digit) may be 0, 2, 4, 6 or 8, i.e. 5 different digits.
So the number of different available codes is:
9 * 10 * 10 * 10 * 5 = 45,000.
Answer: 45,000
