Answer:
year 7 have 135 students
year 9 have 45 students
Explanation:
200=total students
360=value of the whole chart
1/2×360
=180
year 8 have 180students
360-180=180
the students remain are 180
1/4×180
=45
year 9 have 45 students
180-45
=135
year7 have 135 students