Question

find the common factors of 18 and 21

Answer 1

$$\begin{gathered} \mathrm{Factors}\mathrm{of}18=1,2,3,6,9\mathrm{and}18 \\ \mathrm{Factors}\mathrm{of}21=1,3,7,21 \\ \mathrm{Common}\mathrm{factors}\mathrm{of}18\mathrm{and}21=1\mathrm{and}3. \end{gathered}$$