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Week Eleven: WHODUNIT
Solutions due by high noon on Friday, November 20, 2009

Ms. Maroon and Colonel Dijon are nefarious villains who intend to murder poor Professor Prune by poisoning his dinner. Ms. Maroon’s plan is to put arsenic in the apple pie. If Professor Prune were to eat the poisoned pie, there is an 80% chance that he would die. Colonel Dijon plans to put rat poison in the pudding. If Professor Prune were to consume the pudding with rat poison, there is a 60% chance that he would die. Professor Prune does not have much of a sweet tooth and thus will not have both apple pie and pudding with his dinner. On a given evening, there is a 30% chance he will have apple pie, a 60% chance he will have pudding, and a 10% chance that he won’t have either dessert.

1. What is the probability that Professor Prune dies after this meal? Assume that Professor Prune is an otherwise healthy individual and the only cause of death is eating a poisoned dessert.
2. If Professor Prune dies, who is the most likely suspect? Defend your answer by finding the probability of death from each poison.

Submit solutions to Maegan Bos via email, departmental mailbox, or at her office (VAL 210-1).