420. You have steamed 925 miles at 13.5 knots, and consumed 181 tons of fuel. If you have 259 tons of usable fuel remaining, how far can you steam at 16 knots?

Fuel consumption for displacement vessels increases with the cube of speed, resulting in a range decrease proportional to the square of the speed increase; with 259 tons of fuel remaining, the vessel can steam approximately 942 miles at 16 knots.