Question

The total capacity of the water tank is ___ gallons, and the rate of change is ____ gallons per hour.

Answer 1

The total capacity of the water tank is 400 gallons, and the rate of change is 20 gallons per hour. I am not sure of the answer.
Total capacity is 400 because when x=0 then y =400
Rate of change = y2-y1/x2-x1
= 300-400/5-0 = -20 gallons per hour.
Hope this helps.