Problem 3. Raine is a birdwatcher and counts the birds in her garden, which arrive according to a Poisson process of rate A. If an hour passes with no birds, she gets bored and goes to make tea. (a) What is the probability that she doesn't see any birds? (b) How much time on average does she spend birdwatching? Hint: Condition on the time of the rst observed bird. (0) What is the distribution of the number of birds seen