. . "The probability of obtaining no heads i.e. Pr (no H) is one chance in eight (???) i.e. TTT The probability of obtaining 1 head i.e. Pr (1 H) is three chances in eight (???) i.e. TTH, THT, HTT The probability of obtaining 2 heads i.e. Pr (2 H) is three chances in eight (???) i.e. THH, HTH, HHT Finally the probability of obtaining 3 heads i.e. Pr (3 H) is one chance in eight (???) i.e. HHH i.e. We h" . .