At 2 p. m, the level of water in the pool was 10 feet. at 6 p. m, the level of water was 2 feet. determine the constant rate of change of the water. 2 p. m = 10 ft 3 p. m = 8 ft 4 p. m = 6 ft 5 p. m = 4 ft 6 p. m = 2 ft the constant rate of change is " the water drops 2 feet per hour."