Example 1:
$$ \textup{Find the H.C.F. of } 60 \textup{ and } 150$$
Solution:
$$
\begin{array}{|l}
\llap{2~~~~} 60,150 \\ \hline
\llap{3~~~~} 30,75 \\ \hline
\llap{5~~~~} 10,25 \\ \hline
2,5
\end{array}
$$
$$ \textup{H.C.F. }=2×3×5$$
$$ \textup{H.C.F. }=30$$