How would I approach this problem?

There are two boxes containing only purple and yellow pens. Box A has 6 yellow pens and 14 purple pens. Box B has 5 yellow pens and 5 purple pens. A pen is randomly chosen from each box. List these events from least likely to most likely. Event 1: choosing a yellow pen from Box A. Event 2: choosing a yellow or purple pen from Box B. Event 3: choosing a red pen from Box A. Event 4: choosing a yellow pen from Box B. Least likely Most likely Event , Event , Event , Event X 5