The speed of light is 3 x 108 meters per second. Jupiter is approximately 778,500,000,000 meters from the sun. How many seconds will it take for sunlight to reach Jupiter?

There are three bags: a (contains 2 white and 4 red balls), b (8 white, 4 red) and c (1 white 3 red). you select one ball at random from each bag, observe that exactly two are white, but forget which ball came from which bag. what is the probability that you selected a white ball from bag a?