Question

What percent of $5$ litres is $400\,ml$ ?

Answer 1

Hint: We have to find the percentage of one value with respect to another. Firstly we will make the unit of both the values given the same then we will let that $x$ percentage of litres value be equal to the milliliter value and simplify the obtained equation using the percentage term and form a new equation. Finally we will solve the obtained equation and get the desired answer.

Complete step-by-step solution:
We have to find what percent of $5$ litres is $400\,ml$
Firstly we will convert the liter $\left( l \right)$ value into milliliters $ml$ as follows:
$1\,l=1000\,ml$
Multiply both sides by $5$ as follows:
$5\,l=5000\,ml$
Now we have to find what percent of $5000\,ml$ is $400\,ml$.
Let $x\%$ of $5000\,l=400\,l$
Remove the percentage sign and divide the value by $100$ as follows:
$\dfrac{x}{100}\times 5000\,ml=400\,ml$
$\Rightarrow x\times 50\,ml=400\,ml$
Keep the variable on one side and take the rest value on another side as follows:
$\Rightarrow x=\dfrac{400\,ml}{50\,ml}$
$\Rightarrow x=8$
So we get that $8\%\,of\,5$ litres is $400\,ml$ .

Note: Percentage is any number or ratio that can be expressed as a fraction of $100$. For finding the percentage of any number, divide the number by whole and then multiply it by $100$. We can also say that it is a part per hundred. Percentage is represented by $''\%''$ or “per” symbol. It is a dimensionless number as it has no dimension. It can be represented in two forms which are fraction form and decimal form. The general formula for finding the percentage is given as below:
Percentage $=$ (Value$/$ Total Value) $\times 100$
For finding the percentage of a number we use different formula which is given as below:
$P\%$ of Number $=X$