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 six digits.
The first digit cannot be 8 and the last digit must be odd. How many different codes are available?
X -----> possible values 0,1,2,3,4,5,6,7,9 ----> 9 digits
X -----> possible values 10
X ----> possible values 10
X---- possible values 10
X ----> possible values 10
X -----> possible values 1,3,5,7,9 -----> 5 digits
therefore
different codes are=(9)(10)^4(5)=450,000 codes
answer is 450,000 codes