In Exercise 19.12, there is a 0.1 chance that a train will be using the railroad crossing. Given this information, which route should Fred select, and what is the expected number of minutes his trip will require? What is the expected number of minutes Fred would save if he could predict with certainty whether a train will be at the crossing?
In exercise
When Fred takes the direct route to work, he gets there in 30 minutes if no train is at the railroad crossing. When a train is using the crossing, his travel time is 15 minutes longer. His alternative is a route that takes 40 minutes to travel, but has no traffic signals or other delays.