Question

When a class took a math test, 15% of the class failed, 25% made some mistakes (but didn’t fail), and 24 students got perfect scores. How many students were in the class?

Answer 1

There are 40 students in the class.

Explanation:

We are given the following in the question:

Percentage of class that failed = 15%

Percentage of class that made mistakes but did not fail = 25%

Number of students that got perfect score = 24

Percentage of students that got perfect score =

`100\%-\text{Percentage of class that failed}-\text{Percentage of class that made mistakes but did not fail}\\= 100\%-15\%-25\%\\= 60\%`

Let x be the total number of students in the class.

Then, we can write:

`60\% \text{ of } x = 24\\60\% * x = 24\\\\\displaystyle(60)/(100)* x = 24\\\\x = 24* (100)/(60)\\\\x = 40`

Thus, there are 40 students in the class.