Question: Bill, Mary, and Tom have coins with respective proximities p1, p2, p3 of turning up heads. They toss their coins independently at the same times.
a) What is the probability it takes Mary more than n tosses to get a head?
b) What is the probability that the first person to get a head has to toss more than n times?
c) What is the probability that the first person to get a head has to toss exactly n times?
d) What is the probability that neither Bill nor tom get a head before Mary?