1. In responding to a survey on a sensitive topic, such as "have you ever tried marijuana?", many people prefer not to respond in the affirmative. Suppose that 80% of the population have not tried marijuana and all of those individuals will truthfully answer no to your question. The remaining 20% of the population have tried marijuana and 70% of those individuals will lie.
   1. Given someone responds that they have never done marijuana, what is the probability they are lying?
   2. Derive the probability distribution of Y, the number of people you would need to question before one person responds "yes" and determine the expected value of Y.