So these are the four different probabilities. Now example number one tells us use the product rule, which we basically just did by multiplying it to calculate the probability that is obtained when two of those coin slips result in two heads. So this is basically this first square. So heads and heads gives us a probability of one four which is exactly what we obtained by simply multiplying these two values. So we can either do it this way or we can actually use the punished square. Now let's move on to example number two which involves slightly more with genetics because we're using not coin flips but we're producing children.