You have an unfair coin that is designed to come up heads 80% of the time.

a.) what is the probability that you will have to flip the coin exactly three times to get the first head?

b.) on average, how many times must you flip it to get the first head?

c.) on average, how many times must you flip it to get the first tail?

d.) what is the probability that you must flip the coin four or more times to get the first tail?