Math help, Probability-URGENT

1. “A baseball coach is determining the batting order for the team. The team has 9 members, but the coach does not want the pitcher to be one of the first 4 to bat. How many batting orders are possible?”

2. “In morse code, all characters are transmitted using a sequence of dots and dashes. How many different characters can be formed with a sequence of 4 symbols, each of which is a dot or a dash? How many can be formed with a sequence of 1, 2, or 3 symbols?”

3. “Your best friend is taking 4 of the 7 courses you are taking. She has already scheduled her classes. In how many ways can you schedule your classes so that you and your friend shre 4 classes? (Assume that each of the non-shared classes is offered during each of the periods of the day.)”

4. “You visited the Boston Computer museum and bought 4 different robots, one for each of your 4 cousins. When you bought the robots, you intended a specific one for each cousin. After wrapping the packages, however, you realize that you don’t know which robot is in which package. You don’t want to unwrap the packages, so you randomly assign names to the packages.

a. What is the probability that all 4 cousins recieve the robot you intended?

b. What is the probabiity that exactly 3 recieve the robot you intended?

c. What is the probability that exactly 2 recieve the robot you intended? Exactly 1? None?”

Please help me, I’ve tried and tried to get these answered, but I can’t figure them out. I really need help too, or I’ll fail math class.