A book has n typos. The proofreader, Prune, catches each typo with probability p and miss it with probability 1 - p . Let X be the number of typos caught by Prune.
(a) Write down the probability mass function of X.
(b) Compute E[(1 + X)^2]
(c) Compute the conditional probability P(X >= 2|X >= 1)
(d) Conditioned on X = 1 , what is the probability that the 3rd typo is caught?