10 times one says r is equal to 10, but that really means $10,000. Now, it would be a nice business if all you had was revenue and no costs, but you do have costs. You have materials, you have to build your factory, you have to pay your employees, you have to pay the electricity bill. And so you hire a bunch of consultants to come up with what your cost is as a function of x. What your cost is as a function of x. And they come up with a function. They say it is the number of the thousands of pairs you produce cubed minus six times the thousands of pairs you produce squared plus 15 times the thousands of pairs that you produce.