Evaluate 20% of 80.

Hint: A percentage is a number or ratio expressed as a fraction of $100%$. For these kinds of questions, all we need is simple and basic mathematics. We are supposed to find out how much is $20%$ of $80$. To remove the percentage symbol, we are going to divide $20$with $100$ and the multiply with $80$ so as to find out $20%$ of $80$ . Evaluating $20%$ of $80$ is the same as evaluating $80%$ of $20$ since it is only multiplication.

Complete step-by-step solution:
Let us look at an example for better understanding.
For example, we have a number. Let us name it $a$ .
So when we are asked, what is $10%$ of $a$?
It is nothing but $\dfrac{10}{100}\times a=\dfrac{a}{10}$.
So when I add $10$$\dfrac{a}{10}s$ , I would get a complete. $a$
In the same way,$20%$ of $80$ would be the following :
$\Rightarrow \dfrac{20}{100}\times 80=16$.
Now let us look at how much $80%$ of $20$ would give us.
Let us find the value in the same way as we found it $20%$ of $80$.
Upon removing the percentage symbol and dividing with $100$ and multiplying with $20$, we get the following :
$\Rightarrow \dfrac{80}{100}\times 20=16$.
We can see that both of them give us the same answer .
In multiplication, two numbers maybe $a,b$can be multiplied in any way because $a\times b$ is the same as $b\times a$.
This is exactly why $20%$ of $80$ is the same as $80%$ of $20$.
$\therefore $ Hence, $20%$ of $80$ is $16$.

Note: We should be very careful while doing calculations as it may lead to wrong results. Percentage is a very important chapter. It can be clubbed with other concepts and be given as questions. We should be attentive while reading the question. To save time during the exam, we can just do these kinds of calculations in our mind. But this needs heavy practice.