SOLUTION
(a) From the question, water is flowing through a gallon at the rate of 4 gallons per minute. This means that the rate is

Comparing the equation we got to equation of a line which is

So, the slope of the function is 4
(b) Equation for change in V over t, means we find the derivative of V with respect to t. from the linear equation V = 4t, we have

Hence the answer is 4
(c) If there were 4 gallons of water initially in the tank. It means that this initial 4 gallons would be added to the formula, we have

Hence the answer is 4t + 4
(d) If the tank can hold a total of 17 gallons, time t it would take to fill the tank becomes

Hence the answer is 3.25 mins