Question

Kyra observed that 85% of the students at a library liked reading mystery stories. If 30 students at the library did not like reading mystery stories, the number of students at the library who liked mystery stories was _____. (only put numeric values, no other symbols)​

Answer 1

The first thing we must do is find the percentage of students who do not like to read mystery stories.

We have then:

Then, to find the number of students who like to read mystery stories, we can make the following rule of three:

15% ----------------> 30 students

85% ----------------> x

From here, we clear the value of x.

We have then:

the number of students at the library who liked mystery stories was 170