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)

Respuesta :

It is said that 85% of the students liked reading mystery stories. This means the remaining 15% don't like to read these stories. If there are 30 students belonging to the second category, then the number of students who liked reading mystery stories is (30/0.15)*0.85 equal to 170 students out of 200 students. 
The first thing we must do is find the percentage of students who do not like to read mystery stories.
 We have then:
 [tex]100-85 = 15 [/tex]
 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:
 [tex]x = (85/15) * (30) x = 170[/tex]
 Answer:
 
the number of students at the library who liked mystery stories was 170