Question

In a school the ratio of teachers to pupils is 1 : 20. If there are 12 teachers, how
many pupils are there in the school?

Answer 1

Dear Student,

$$\begin{gathered} Letthenumberofpupilsbex. \\ Wearegiventhattheratiooftheteacherstopupilsinaschoolis1:20;andthereare12teachers. \\ \therefore 1:20=12:x \\ \Rightarrow \frac{1}{20}=\frac{12}{x} \\ \Rightarrow x\times 1=12\times 20 \\ \Rightarrow x=240pupils \end{gathered}$$