And one of these things that you'll find in probability is that you can always do a more interesting problem. So now I'm going to think about, I'm going to take a fair coin, and I'm going to flip it three times. And I want to find the probability of at least one head out of the three flips. So the easiest way to think about this is how many equally likely possibilities there are. In the last video we saw, if we flip a coin three times, there's eight possibilities. For the first flip, there's two possibilities. Second flip, there's two possibilities.