If a coin is tossed a sequence of times, what is the probability that the first head will occur after the fifth toss, given that it has not occurred in the first two tosses?
# Probability of event A intersect B
prob_A_intersect_B <- 1/8
# Probability of event B
prob_B <- 1 - 1/2 * 1/2
# Probability of A given B
prob_A_given_B <- prob_A_intersect_B / prob_B
prob_A_given_B## [1] 0.1666667