Well, there's six different people who could be in chair number one. Let me do that in a different color. There are six people who could be in chair number one. Six different scenarios for who sits in chair number one. Now, for each of those six scenarios, how many people, how many different people could sit in chair number two? Well, in each of those six scenarios, we've taken one of the six people to sit in chair number one, so that means you have five out of the six people left to sit in chair number two. Or another way to think about it is there's six scenarios of someone in chair number one, and for each of those six, you have five scenarios for who's in chair number two.