Question

If three-fourth part of a post is under water, then what per-cent is above water?
A) $$25\% $$
B) $$30\% $$
C) $$40\% $$
D) $$50\% $$

Answer 1

Hint: The problem has given us a fraction of the post that is underwater. We need to find the percent of the post that is above water. So, first let us consider the water to be $$100$$. Then, we can use the given fraction and convert it to percentage, we will get the percentage of the post that is present under water. Now, we can subtract this from the total percentage to get the percent of the post that remains above water.

Complete step by step solution:
Let us represent the given problem as follows:

This is a rough diagram, note that the shape of the object is not our concern as per the given problem.
Now, let us consider the total part of the water to be $$100$$.
We have been given that $${\dfrac{3}{4}^{th}}$$ part of the $$100$$ is under water.
Let us find the percent,
$$ \Rightarrow \dfrac{3}{4} \times 100 = 75\% $$
Therefore, $$75\% $$of the post is under water.
Let us now find out the percent of the post that is above water.
To find that, we will subtract the percent of the post present under water from the total.
$$ \Rightarrow 100 - 75 = 25\% $$
Therefore, $$25\% $$ is the final answer.
Hence, option (A) is the correct answer.
So, the correct answer is “Option A”.

Note: Read the question carefully, it asks for the percent of post ‘above water’, so do not stop the simplification when you find the percent of post ‘below water’. And, draw a diagram for a better understanding, irrespective of the shape of the post. Alternate method would be to subtract the fraction from total and then convert it into percent in the end.