How many additional teachers will have to be hired to reduce the ratio to 1:20 ?

Question

Jefferson School has  students. The teacher-pupil ratio is  How many additional teachers will have to be hired to reduce the ratio to ?

Answer 1

First you need to use proportions to find the current number of teachers. Let x = the number of teachers.

1/30 = x/1800

Solving for x, x= 60

So there are currently 60 teachers.

They want the ratio of teachers to students to be 1/20. Let's find the number of teachers they would need and call it y.

1/20 = y/1800

Y = 90.

So if they have 60 teachers now and need 90 teachers, how many would they need to hire???