Box 1 contains 30 red and 70 white balls, box 2 contains 50 red and 50 white balls, and box 3 contains 75 red and 25 white balls. the three boxes are all emptied into a large box, and a ball is selected at random. if the selected ball is red. (a) what is the probability that it came from box 1? (b) what is the probability that it came from box 1 or box 2? (c) what is the probability that it did not come from box 3