Question

There are 45 students in a class and $\frac{3}{5}$ of them are boys. How many girls are there in the class?

Answer 1

$$\begin{gathered} \frac{3}{5}\mathrm{of}45=\frac{3}{5}\times 45=27 \\ \mathrm{Therefore},27\mathrm{students}\mathrm{are}\mathrm{boys}. \\ \mathrm{Number}\mathrm{of}\mathrm{girls}=\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{students}\mathrm{in}\mathrm{the}\mathrm{class}-\mathrm{Number}\mathrm{of}\mathrm{boys} \\ \mathrm{Number}\mathrm{of}\mathrm{girls}=45-27=18 \\ \mathrm{Therefore},18\mathrm{students}\mathrm{are}\mathrm{girls}. \end{gathered}$$