The probability of getting heads on the first toss is 1/2 .
Then, the probability of getting heads on the second toss is 1/2 .
Then, the probability of getting heads on the third toss is 1/2 .
The probability of all three things happening is ...
(1/2) x (1/2) x (1/2) = 1/8 = 0.125 = 12.5% .
