Let's Make a Deal: The Player's Dilemma

Implementing conditional probability concepts and understanding their practical implications can be difficult tasks for the student. Textbook problems are often set in artificial situations that neither require nor inspire real-world thinking on the student's part. Recently an old problem appeared in Parade Magazine in a new setting that is realistic, widely known, and invariably of great interest. The solution and failed attempts at solution are rich in their lessons in thinking about conditional probability.