What's the question mark? 21 plus what is equal to 24? We can, of course, you might just, well, it's going to be three, or if you want to, you could say, well, question mark is going to be, question mark is going to be equal to, is going to be equal to 24 minus 21, which is, of course, three. Which, of course, let me just write this down. The question mark is equal to three. The missing age, you were able to figure it out based on the information you had, because you had the mean, you were able to figure out that behind the splotch, that behind the splotch, you had a three. It's exciting.