In the city of Bedford, there are two taxicab companies. Blue and Green. As you may suppose. Blue cabs are blue and Green cabs are green. The Blue company operates 90% of all cabs in the city and the...

In the city of Bedford, there are two taxicab companies. Blue and Green. As you may suppose. Blue cabs are blue and Green cabs are green. The Blue company operates 90% of all cabs in the city and the Green company operates the rest. One dark evening, a pedestrian is killed by a hit-and-run taxicab. There was one witness to the accident. In court, the witness' ability to distinguish cab colors in the dark is questioned, so he is tested under conditions similar to those in which the accident occurred. If he is shown a green cab, he says it is green 80% of the time and blue 20% of the time. If he is shown a blue cab, he says it is blue 80% of the time and green 20% of the time.