Many schools have a recommended students-teacher ratio as 35:1. Next year, school expects an increase in enrolment by 280 students. How many new teachers will they have to appoint to maintain the students-teacher ratio?
Students: teacher ratio = 35:1
It shows every 35 students-one teachers should available in the school.
In the school, number of teachers required for 280 students = 
= teachers.
104