Answer
$S=\{HHH, HHT, HTH,THH,HTT,THT,TTH,TTT \}$ and the probability of each outcome is $\frac{1}{8}$.
Work Step by Step
For tossing three fair coins, we can construct the sample space as $S=\{HHH, HHT, HTH,THH,HTT,THT,TTH,TTT \}$ and the probability of each outcome is $\frac{1}{8}$.