Number 4 (6 points) Shing-Tung has forgotten his computer password, but remembers that it consists of three digits between 0 and 9 followed by two lower-case letters. If he's allowed three attempts before he is locked out of his account, what is the probability that he'll be able to access his account?

Number 5 (6 pts) A red die and a black die are rolled once each. (a) What is the probability that the number on the black die is greater than the one on the red die?(b) Say that the red die is a 3. What is the probability that the sum of the two dice will be 8 or less?(c) Say that you're told that the sum of the dice is 9. What is the probability that the black die was a 5 or a 6?