There are two bags containing only purple and white marbles. Bag A has 12 white marbles and 8 purple marbles. Bag B has 6 white marbles and 10 purple marbles. A marble is randomly chosen from each bag. List these events from the least likely to the most likely. Event 1: choosing a white marble from Bag A. Event 2: choosing a purple marble from Bag B. Event 3: choosing a yellow marble from Bag A. Event 4: choosing a white or purple marble from Bag B.