Alex flips a fair coin four times. What is the probability that he flips heads three times in a row?
The probability of getting 3 heads in a row is:
1/2 x 1/2 x 1/2 ==1 / 8
This graph might help explain:
There are 24 = 16 possible outcomes
there are only 2 ways to get 3 heads in a row: t h h h and h h h t
2/16 = 1/8 as posted