If 3 out of 4 parts of Earth's surface is covered by water, then the percentage of Earth's surface covered by water is .

The correct option is D 75%


Parts covered in water = 3

Total number of parts = 4

So, fraction of Earth covered in water $=\frac{3}{4}$

Percentage is a fraction with its denominator as 100.

Converting $\frac{3}{4}$ into a fraction with 100 as its denominator, you get:

$\frac{3}{4}=\frac{3\times 25}{4\times 25}=\frac{75}{100}$

So, the percentage form of $\frac{3}{4}$ is 75%.

∴ 75% of Earth's surface is covered in water.