How do you find \[40\] is \[0.80\% \]?

Hint: In this question they have asked how to find \[40\] is \[0.80\% \] in some particular number. If we need to find the value of a certain percentage from a whole, we have to multiply the percentage to the whole value to get its percentage value. Here we will find the whole value using that method.

Formula used: Percentage= $\dfrac{{{\text{part}}}}{{{\text{whole}}}} \times 100$
Part = ${\text{whole}} \times \dfrac{{{\text{percentage}}}}{{{\text{100}}}}$

Complete step-by-step solution:
Here, we need to prove how to find \[40\] is \[0.80\% \] in some particular number.
We know that to find the value of a certain percentage from a whole, we have to multiply the percentage to the whole value.
That is Part = ${\text{whole }} \times\dfrac{{{\text{percentage}}}}{{{\text{100}}}}$
Now, that we know this we will find the whole value first,
$ \Rightarrow 40 = x \times \dfrac{{0.80}}{{100}}$
Then,
$ \Rightarrow x = 40 \times \dfrac{{100}}{{0.80}}$
$ \Rightarrow x = 5000$
Now that we have the whole value,
We can say that $40$ is found by using Part =${\text{whole }} \times\dfrac{{{\text{percentage}}}}{{{\text{100}}}}$, as \[40\] is \[0.80\% \] of \[5000\] because \[5000 \times 0.008 = 40\].

Therefore the answer for the given question is 5000.

Note: It is given that \[40\] is \[0.80\% \] in some whole value. And we need to find how it is found.
For that first,
Divide the percentage \[0.80\% \]by\[100\]
\[ \Rightarrow \dfrac{{0.80}}{{100}} = 0.008\]
Now divide the given number by\[0.008\], that is
\[ \Rightarrow \dfrac{{40}}{{0.008}}\]
Now we will find the whole number where \[0.8\% \] is \[40\]
\[ \Rightarrow \dfrac{{40}}{{0.008}} = 5000\]
Therefore, \[40\] is \[0.80\% \] of \[5000\] because \[5000 \times 0.008 = 40\].
Further note that, A percentage is a way to express a number as a part of a whole
To calculate a percentage, we look at the whole as equal to \[100\% \] and that’s why the calculations regarding percentages always contain the number \[100\] in it. We can say that the word percent is percent that is something like\[\;25\] percent means “\[\;25\] percent” or “\[\;25\] per \[100\]”.