Question

How much of the Earth’s surface is covered with water?

(A) About two-third

(B) About one-fourth

(C) About three-fourth

(D) About one-third

Answer 1

Hint: About 29% of the Earth’s crust is made up of land. With this in mind, try and work out how much of the rest is made up of water.

Complete Answer:

Let us do a thorough analysis of what covers the Earth’s crust for us to be able to answer this question in detail:

The Earth is often compared to a majestic blue marble due to the prevalence of water on the planet's surface. While water itself is not blue, it gives off blue light upon reflection.

In simplest terms, water makes up about 71% of the Earth's surface, while the other 29% consists of continents and islands.

To break the numbers down, 96.5% of all the Earth's water is contained within the oceans as salt water, while the remaining 3.5% is freshwater lakes and frozen water locked up in glaciers and the polar ice caps. Of that fresh water, almost all of it takes the form of ice: 69% of it, to be exact. If you could melt all that ice, and the Earth's surface was perfectly smooth, the sea levels would rise to an altitude of 2.7 km.

With this information, let us now analyse the options.

We can eliminate options b) About one-fourth (25%) and d) About one-third (33%) straight off the bat as these show that land is more prevalent than water on the Earth’s surface. Of the other two alternatives, About three-fourth (75%) is closer to the real figure (71%) when compared to About two-third (66.6%). 

Therefore, by this process of elimination, we can safely conclude that the answer to this question is (C).

Note: This question could also be rephrased as the space occupied by the hydrosphere on the Earth’s surface. If this occurs, then do not get confused as it means the same thing.