Question

Student : teacher ratio at a school is 15: 1.

(i) How many students are there if there is a total of 320 students and staff?
(ii) What would be the new student: teacher ratio if two more teachers joined the school?

Answer 1

300 students and 150 : 11

Explanation:

(i)

sum the parts of the ratio , 15 + 1 = 16 parts

divide the total students/staff by 16 to find the value of one part of the ratio.

320 ÷ 16 = 20 , then

number of students = 15 × 20 = 300

(ii)

number of staff = 320 - 300 = 20

if 2 more teachers join the school then there is a total of 22 staff

student : teacher = 300 : 22 = 150 : 11