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

30 additional teachers will have to be hired to reduce the ratio to 1:20.

Step-by-step explanation:

Given that Jefferson School has 1800 students, and the teacher-pupil ratio is 1:30, to determine how many additional teachers will have to be hired to reduce the ratio to 1:20, the following calculation must be performed:

30 = 1800

1 = X

1800/30 = X

60 = X

20 = 1800

1 = X

1800/20 = X

90 = X

90 - 60 = 30

Therefore, 30 additional teachers will have to be hired to reduce the ratio to 1:20.