Question

Find the HCF of $168$and $126$

Answer 1

Find HCF of the given numbers

Prime factors of:

$$\begin{gathered} 168=2\times 2\times 2\times 3\times 7 \\ 126=2\times 3\times 3\times 7 \end{gathered}$$

Common factors of $168$ and $126$ are $2\times 3\times 7$

So, the highest common factor is $2\times 3\times 7=42$

Hence, HCF of $168$ and $126$ is $42$.