Given the rate of water flow is given by: r(t)=85e^(-0.04t) thus the amount of water flow in the first hour when t=1, will be: r(1)=85e^(-0.04*1) =81.667 thus the amount of water that flowed out will be: 85-81.667 =3.333 liters
Mathematical domain is all numbers, as all numbers can be multiplied by 4. However, this is not reasonable as negative lengths don't exist, so the reasonable domain would be all positive numbers.