A ship is bunkering fuel in port. The rate of bunker is decided to be maintained at 400 cubic meters per hour. The ship fuel tanks have a capacity of 3600 cubic meters. Assuming that the the rate of bunker remains constant throughout and that the fuel tanks are initially filled up with 250 cubic meters, draw a graph showing the tanks' level condition over time. From the graph,
1. After how much time (in hours) would the fuel tanks be filled to 85% capacity?
2. After 5.5 hours, how much more fuel is needed to be bunkered if the Chief Engineer only wants to bunker 90% of the ship's capacity.