John throws a coin until a series of three consecutive heads or three consecutive tails appears. What is the probability that the game will end after the fourth throw?
Please explain your answer.
B for me.
The probability of getting heads=probability of getting tails=1/2
If the game ends after the fourth throw, there are two possibilities.
T,H,H,H or H,T,T,T.
Therefore, required probability= 2 * [(1/2)^4] = 2/16 (or 1/8