The sample space for tossing a coin three times contains all possible combinations of heads (H) and tails (T). These combinations are the outcomes of the three tosses. The sample space is:

$S = \{ HHH, HHT, HTH, HTT, THH, THT, TTH, TTT \}$

Now, for the event that the first toss is heads, we only consider the outcomes where the first toss is H. The outcomes for this event are:

$\{ HHH, HHT, HTH, HTT \}$

Would you like further details on any step, or do you have any questions?

Here are 5 related questions to explore further:

1. What is the probability of getting exactly two heads in three tosses?
2. What is the probability of getting at least one head in three tosses?
3. How many outcomes result in no heads?
4. What is the probability of getting tails on all three tosses?
5. What is the probability of getting heads on the second toss?

Tip: In probability, the total number of outcomes in the sample space is crucial for calculating the likelihood of events. Make sure to count all possible outcomes carefully!