6. (8 points) License plates in Florida have the form A46DUFE; that is, a letter followed by 2 digits followed by 4 more letters. SHOW YOUR WORK FOR ALL PARTS! (a) Find the number of possible license plates if repetition is allowed. (b) Find the number of possible license plates if repetition is not allowed. 7. (8 points) A particular firm has 6 vacancies to fill from 15 applicants. The applicants consist of 7 women and 8 men. SHOW YOUR WORK FOR ALL PARTS! (a) Calculate the number of ways in which these vacancies could be filled if there are no restrictions. (b) Calculate the number of ways in which these vacancies could be filled if the firm decides that 3 of the 6 vacancies shall be filled by women and 3 by men. (c) Calculate the number of ways in which these vacancies could be filled if there is at least 4 women