Description: In this example we are figuring out the probability of randomly picking a non-blue marble from a bag. Again, we'll have to think about the possible outcomes first. Created by Sal Khan. And then we have 3 green marbles, let me draw those 3, so 1, 2, 3. What is the probability of randomly selecting a non-blue marble from the bag? And the way you just think about it is what fraction of all of the possible events meet our constraint?*Teacher Advisor is 100% free.