Question

What is \[10\% {\text{ of }}40\]?

Answer 1

Hint: We use the concepts of percentages and its formulas to solve this problem. We will define the percentage and look at some examples of them. Generally, the percentage can be calculated using formula \[\dfrac{{{\text{parts}}}}{{{\text{total}}}} \times 100\].

Complete step by step answer:
In mathematics, a ratio or a number expressed as a fraction of 100 is called a percentage. It is denoted by the symbol ‘%’. Percentage is a dimensionless number. It has no unit of measurement. Percentages are often used to express a proportionate part of a total.
Suppose that, there are \[m\] total objects and we took \[n\] out of them. Then, the percent of things that we took is calculated by formula \[\dfrac{{{\text{parts}}}}{{{\text{total}}}} \times 100\]
So, the percentage that we took is \[\dfrac{n}{m} \times 100\]
For example, take this situation. There are 10 boys and 10 girls in a class.
So, there are a total of 20 students in that class. So, percentage of boys in the class is equal to \[\dfrac{{10}}{{20}} \times 100\]
Which is equal to \[50\% \].
If we need to calculate \[x\% \] of a whole, then we use the formula \[\dfrac{x}{{100}} \times (total)\]
It simply means, if \[x\] parts are there in a hundred parts, then how many parts will be there in total parts.
So, here, we need to calculate \[10\% {\text{ of 40}}\]
\[ \Rightarrow \dfrac{{10}}{{100}} \times 40\]
\[ \Rightarrow \dfrac{{400}}{{100}}\]
So, finally, it is equal to 4.
So, \[10\% {\text{ of 40}}\] is equal to 4.

Note:
If the percentage is equal to \[100\% \], then it represents a whole unit. And \[50\% {\text{ and 25% }}\] represents half and quarter parts of a whole. The word percent means “per-cent” where ‘cent’ means hundred.
So, percent means that ‘per every hundred’. So, in a simple way, percentage defines the number of parts of units present in every 100 parts.