Which of the following statements is correct?

a- Approximately, 71 percent of the earth’s surface is covered with water.

b- Freshwater constitutes only about 30 percent of the total water on Earth. 

Only statement a is correct.

Water is a cyclic resource with abundant supplies on the globe. Approximately, 71 percent of the earth’s surface is covered with it but freshwater constitutes only about 3 percent of the total water. In fact, a very small proportion of freshwater is effectively available for human use. The availability of freshwater varies over space and time. The tensions and disputes on sharing and control of this scarce resource are becoming contested issues among communities, regions, and states.