Question

The access code for a? car's security system consists of fivefive digits. the first digit cannot be zerozero and the last digit must be eveneven. how many different codes are? available?

Answer 1

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