Question

The ratio of the number of Grade 6 students to the number of Grade 7 students to the number of Grade 8 students in a school is 3 : 3.4 : 3.2 . If the school has 480 students in these grades, how many are in Grade 8?

Answer 1

160

Explanation:

The fraction of students in grade 8 is ...

(grade 8 students)/(total students in all grades)

= 3.2/(3 +3.4 +3.2) = 3.2/9.6 = 1/3

Then the number of students in grade 8 is ...

(1/3)(480 students) = 160 students . . . in grade 8