Question

Use the prime factorisation method to find the LCM of the following groups of numbers:

$6,12and18$

Answer 1

LCM of $6,12and18$ is the smallest number among all common multiples of $6,12and18$

By prime factorization method,

$$\begin{gathered} 6=2\times 3 \\ 12=2\times 2\times 3 \\ 18=2\times 3\times 3 \\ LCM(6,12,18)=2\times 2\times 3\times 3=36 \end{gathered}$$

Hence, $LCM(6,12,18)=36$ .