Question

Which pair of numbers has a Greatest common factor of 6?6 and 1212 and 243 and 18

Answer 1

Firstly, solve 6 and 12.

$\begin{gathered} 6=2\times3 \\ 12=2\times2\times3 \\ \\ \text{the greatest common factor is 2}\times3=6 \end{gathered}$

Now, 12 and 24

$\begin{gathered} 12=2\times2\times3 \\ 24=2\times2\times2\times3 \\ \text{the greatest common factor is 2}\times2\times3=12 \end{gathered}$

Now, 3 and 18

$\begin{gathered} 3=3 \\ 18=2\times3\times3 \\ \text{The greatest common factor is 3.} \end{gathered}$

So, 12 and 24 have the greatest common factor.