Question

On a particular day $ 16\% $ of the students in a class remained absent. If 42 students were present on that day, find the total strength of the class.

Answer 1

Hint: In this problem, we are given the percentage value of absent students and the number of students who are present. We will first find the percentage of present students by subtracting the percentage of absent students from 100. From this percentage value and number of present students, we can determine the total number of students in the class.
Formula used:
 $ a\% $ of $ b = \dfrac{{a \times b}}{{100}} $

Complete step-by-step answer:
Here, we are given that $ 16\% $ of the students in a class remained absent on a particular day.
First, we will find the percentage of the students present in the class on that day. This is done by subtracting the percentage of absent students from 100.
Thus, the percentage of present students $ = 100 - 16 = 84\% $
We are also given that the number of students present in the lass on that particular day was 42 which is $ 84\% $ of the total strength as we have determined.
Now, for finding the total number of students in the class, we will use the formula $ a\% $ of $ b = \dfrac{{a \times b}}{{100}} $
We have seen that
 $ 84\% $ of the total strength is 42
Let the total number of students in the class is $ x $ . Therefore, $ 84\% $ of $ x $ is 42.
 $
   \Rightarrow \dfrac{{x \times 84}}{{100}} = 42 \\
   \Rightarrow x = \dfrac{{42 \times 100}}{{84}} \\
   \Rightarrow x = 50 \;
  $
Thus, the total strength of the class is 50.
So, the correct answer is “50”.

Note: Here, we have determined the total number of students by using the percentage value and number of present students. Now, if we want to know the number of students who remained absent on the particular day, we can get it by subtracting the number of present students from the total strength of the class which is $ 50 - 42 = 8 $ . Thus, 8 students were absent in the class.