Suppose that a sequence of independent tosses are made with a coin for which the probability of

Question:

Suppose that a sequence of independent tosses are made with a coin for which the probability of obtaining a head on each given toss is 1/30.
a. What is the expected number of tails that will be obtained before five heads have been obtained?
b. What is the variance of the number of tails that will be obtained before five heads have been obtained?