Well, let's think about what we have here. You know that you need 33.09 ounces for 20,000 gallons. Intuitively, it makes sense that to make half as many gallons, you'd also need half as much chemical, yeah? So how many ounces of chemical would you need to make 10,000 gallons? Suppose, then, that you wanted to make a third as many gallons. How much chemical would you need then? Finally, to get from 20,000 gallons to 2,500 gallons, what did you divide by? What, then, does that suggest about how many ounces of chemical you need?