Well, we know what the temperature of the t is, so we just have to figure out the temperature of the biscuits to figure out how much cooler they are than the t. And to figure out the temperature of the biscuits, we can essentially just use the exact same idea. We can say how much did the, we know that the biscuits started off at 100 degrees Celsius, and we can say, well, how much did they cool down, or what was their change in temperature over the 10 minutes? If we know the change in temperature and we know it started at 100 degrees, then we can use that information to get what its temperature is at 10 minutes, and then we can answer their question. So the change in temperature over those 10 minutes is just the definite integral from zero to 10 of this business right over here. Of, let me just write it so you see it's the exact same pattern as what we saw over here. This was for the cookies, now we're talking about the biscuits. And this right over here is going to be the definite integral from zero to 10.