Question

A realtor uses a lock box to store the keys to a house that is for sale. The access code for the lock box consists of four digits. The first digit cannot be zero and thelast digit must be even. How many different codes are available? (Note that is considered an even number.)

Answer 1

Answer:

4500 different codes

Explanation:

To know the number of codes available, we will use the rule of multiplication, so:

9 x 10 x 10 x 5 = 4500

1st 2nd 3rd 4th

Because there are 10 digits in total, if the first digit can't be zero, we have 9 options for the first digit and if the 4th digit must be even, there are only 5 digits that are even (0, 2, 4, 6, and 8).

Therefore, there are 4500 different codes available.