Water makes up about 71% of the Earth’s surface, while the other 29% consists of continents and islands. 96% of all the Earth’s water is contained within the oceans as salt water, while the remaining 4% is fresh water located in lakes, rivers, glaciers, and the polar ice caps.

The total volume of water on Earth is 1,386 million cubic kilometers.

a. What is the volume of salt water.

b. What is the volume of fresh water.