You flip a coin three times and observe the outcome. Describe (list) the sample space of possible outcomes, using H or T for each outcome. Include probabilities for each event.

You should post all of your questions in one message, not several. Then, you should explain what you've done and why you're stumped.

If you flip a coin three times, you'll get

1. head or tail
2. head or tail
3. head or tail

What are the possibilities?

HHH
HHT
... continue with one tail
HTT
... continue with two tails
TTT

You get the picture. Figuring probabilities is simply counting the possibilities, n. Each possibility is 1/n.