We have the following:
We can calculate the answer by means of a proportion.
We know that 36 is 30%, how do we want to know the total, we must calculate 100%, as follows:
[tex]\begin{gathered} 36\rightarrow30 \\ x\rightarrow100 \\ x=\frac{100\cdot36}{30} \\ x=120 \end{gathered}[/tex]The total number of students in the choir is 120
