Question

What is 9% of 50?

Answer 1

Hint: To find the value of 9% of 50, we have denoted this mathematically. For this, we will denote ‘of’ as a multiplication sign. Then, we have to convert 9% into its number form by dividing 9 by 100. Then, we have to simplify.

Complete step-by-step answer:
We have to find the value of 9% of 50. Let us first denote this mathematically.
$= 9\%\times 50...\left( i \right)$
Now, we have to convert 9% in its number form. For this, we have to divide 9 by 100.
$= 9\%=\dfrac{9}{100}$
Let us substitute the above value in (i). We will get
$= \dfrac{9}{100}\times 50$
Let us simplify the above result. We have to cancel the zero from 100 and 50.
$= \dfrac{9}{10\require{cancel}\cancel{0}}\times 5\require{cancel}\cancel{0}$
The above operation will result in
$= \dfrac{9}{10}\times 5$
Let us cancel the common factor 5 from the denominator and 5 in the numerator.
$= \dfrac{9}{{{\require{cancel}\cancel{10}}^{2}}}\times \require{cancel}\cancel{5}$
The above simplification will result in
$= \dfrac{9}{2}$
Let us write the above result in the decimal form.
\[2\overset{4.5}{\overline{\left){\begin{align}
  & 9.0 \\
 & -8 \\
 & \_\_\_\_ \\
 & \text{ }\text{ }\text{ }10 \\
 & -10 \\
 & \_\_\_\_ \\
 & \begin{matrix}
   {} &\text{ }\text{ } 0 \\
\end{matrix} \\
\end{align}}\right.}}\]
Therefore, the decimal of $\dfrac{9}{2}$ is 4.5.
Hence, 9% of 50 is $\dfrac{9}{2}$ or 4.5.

Note: Students must know how to convert a number into its percentage form and vise-versa. They must also know to multiply and simplify fractions. They must also know to find the decimal value of a fraction. In mathematics, we usually denote ‘of’ as multiplication. In these types of questions, we must convert the percentage into numbers first and then simplify as much as possible. We must first cancel the common factors so that the simplification will be easier.