Assume that the car lot contains 40 percent Corvettes, 30 percent BMWs, and 30 percent Porches. Of the Corvettes, 80 percent have navigation systems, 10 percent of the BMWs have navigation systems, and 30 percent of the Porches have navigation systems. Furthermore, 70 percent of the Corvettes, 60 percent of the BMWs, and 90 percent of the Porches are silver. The property of being silver is independent from having a navigation system. You are assigned a car at random.

If the car has a navigation system and is silver, what is the probability that it is a Corvette?