Question

Find LCM and HCF of 3930 and 1800 by prime factorisation method.

Answer 1

By prime factorization method,
Factors of 3930 and 1800 are,
$\begin{array}{cc}2& 3930\\ 3& 1965\\ 5& 655\\ 131& 131\\ & 1\end{array}$ $\begin{array}{cc}2& 1800\\ 2& 900\\ 2& 450\\ 3& 225\\ 3& 75\\ 5& 25\\ 5& 5\\ & 1\end{array}$
So, $3930=2\times 3\times 5\times 131$
$1800=2\times 2\times 2\times 3\times 3\times 5\times 5$
then, $HCF=2\times 3\times 5=30$
and, $LCM=2\times 2\times 2\times 3\times 3\times 5\times 5\times 131$
$=235800$