How long would a tunnel from NYC to San Fran. would be if you dig it through the earth as short as possible? If you traveled directly on the surface? What is you confidence bound (length +/-)? You are waiting for a bus which it takes a round trip of 10 minutes to complete (starts again when it completes one tour). What is your expected waiting time if you arrive at a random time? (uniform from 0 to 10, so 5min). Then, an extension: There is an ice cream shop somewhere on the bus route. The bus driver flips a fair coin every time it passes by it and f "H", spends 10 minutes to eat ice cream and then continue the tour. What is your expected waiting time now? What is the coin is biased?