All the possible outcomes for three tosses of the coin are:H-H-HT-H-HH-T-HH-H-TT-H-TT-T-HH-T-TT-T-TThese eight possible outcomes are the sample space.To find the probability of tossing heads exactly twice look down the sample space list and find any outcome that has exactly two H's. The possibilities that you can get two H’s in an outcome are THH, HTH, and HHT. It means that exactly three of eight possible outcomes has exactly 2 heads. One way to view the sample space is to raise the number of possible outcomes in each trial to the power of the number of trials. You are a total of eight (8) sample space on tossing a coin three times.