Assuming the earth to be a sphere of radius 6370 km, how many square kilometres is area of the land, if three-fourth of the earth’s surface is covered by water?

Explanation

To solve the problem of finding the area of land on Earth, given that three-fourths of its surface is covered by water, follow these steps:

### Step 1: Calculate the total surface area of the Earth
The formula for the surface area \( A \) of a sphere is given by:
\[ A = 4 \pi r^2 \]
where \( r \) is the radius of the sphere. Given that the radius of the Earth is \( 6370 \) km, we can substitute this value into the formula.
...