Nancy is filling an aquarium for her fish. She fills it halfway and goes to answer the door. While she's gone, her cat knocks the aquarium over and spills half the water in it. Then Nancy comes back and triples the amount of water in the aquarium. If the aquarium is 4 feet long, 6 feet wide, and 3 feet high, how many cubic feet of water are in the aquarium? Let's be accurate as possible.
First calculate the volume of the aquarium by multiplying its length, width and height: 4 ft * 6 ft * 3 ft = 72 cubic ft. Then figure out what proportion of the aquarium is full after the cat knocks it over: 1 / 2 * 1 / 2 = 1 / 4. Then figure out what proportion of the aquarium is full after Nancy refills it: 3 * 1 / 4 = 3 / 4. Now multiply the proportion of the aquarium that's full by the aquarium's volume to find out how much water is in it: 72 cubic ft * 3 / 4 = 54 cubic ft.
The answer: 54.