Well, there would be n possibilities for who's in the first position or which object is in the first position. And then for each of those possibilities, there would be n minus one possibilities for which object you choose to put in the second position because you've already put one into that position. Now for each of these n times n minus one possibilities where you've placed two things, there would be n minus two possibilities of what goes in the third position and then you would just go all the way down to one. And this thing right over here is exactly what we wrote over here. This is equal to, this is equal to n factorial. But if we directly applied this formula, if we applied this formula, this would need to be n factorial over n minus n factorial. And then you might see why this is interesting because this is going to be n factorial over zero factorial.