Every flip is an independent event. What happened in the past in these flips does not affect the probabilities going forward. So the probability of getting heads on the first flip in no way, or the fact that you got heads on the first flip, in no way affects that you got heads on the second flip. So if you can make that assumption, you could say that the probability of getting heads and heads, or heads and then heads, is going to be the same thing as the probability of getting heads on the first flip times the probability of getting heads on the second flip. We know the probability of getting heads on the first flip is one-half, and the probability of getting heads on the second flip is one-half. And so we have one-half times one-half, which is equal to 1 4th, which is exactly what we got when we tried out all of the different scenarios, all of the equally likely possibilities. Let's take it up another notch.