Problem 3 Suppose a monkey is standing 5 steps from the edge of a cliff. Every second, the monkey either takes one step towards the cliff or one step away from the cliff. He steps towards the cliff with probability p and away with proba- bility 1 -- p. The monkey has no regard for his own life, and continues to do this indefinitely.
a) What is the largest value of p for which the monkey will have no more than a 50% chance of eventually falling off the cliff?
b) Suppose we have the same situation but with p = 0.55. What is the probability that he eventually falls off the cliff? What is the expected length of time for this to happen?