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

You didn't say anything so I have to assume that other than the two conditions mentioned for the fist and last digit, all numbers 0-9 are permissible.

1st digit cannot be a 5. Therefore there are 9 possibilities

digits 2-5 can be any digit. There are 10 possibilities for each. There are 4 digits involved, so there are 104 possibilities.

Finally the last, 6th digit must be odd. Therefore there are 5 possibilities.

The number of different possible codes is

9 x 104 x 5 = 45 x 104 = 450,000

54 different codes should be right