Question

What is $18\%$ of $150$ ?

Answer 1

Hint: To calculate the percentage of a number, of the form x% of y, then If we can use the formula $\dfrac{x}{100}\times y=a$. We will substitute the values of x as 18 and y as 150 to get the value of a. This will be the required answer.

Complete step by step answer:
Percentage is used to describe a part of a whole. Percentage means per $100$. It is a dimensionless quantity.i.e., it has no dimension.
For example:
$1\%$ is equivalent to $\dfrac{1}{100}$ fraction.
To calculate the percentage of a number, we use the formula
$x\%$ of $y=a$
If we remove the percentage sign, then we would need to express the given percentage as a fraction by dividing the value by $100$. So, the new formula would become
$\dfrac{x}{100}\times y=a$
Here, we need to find $18\%$ of $150$.
First, we will convert the given percentage into fraction.
Here, $18\%=\dfrac{18}{100}$
“Of” means to multiply, so
$18\%$ of $150$ means
$\dfrac{18}{100}\times 150$,
Let us consider
$\begin{align}
  & \dfrac{18}{100}\times 150=a \\
 & \Rightarrow a=\dfrac{18\times 150}{100} \\
 & \Rightarrow a=\dfrac{18\times 3}{2} \\
 & \Rightarrow a=27 \\
\end{align}$

So, $18\%$ of $150$ is $27$.

Note: In such types of questions, a student might forget to convert the percentage into fraction and may directly multiply the percentage with the given value. So, that answer would be wrong as the percentage first needs to be converted into a fraction through dividing the percentage by $100$. Then the fraction needs to be multiplied with the given value to obtain the final answer.