Question

Find L.C.M of $15,20$ and $40$ by prime factorisation method.

Answer 1

Step 1: Prime factorisation of the given numbers.

Step 2: Find L.C.M. of the given numbers.

$$\begin{gathered} 15=3\times 5 \\ 25=5\times 5 \\ 40=2\times 2\times 2\times 5 \end{gathered}$$

L.C.M. $=3\times 5\times 5\times 2\times 2\times 2\times 2=600$

Therefore, L.C.M. of $15,20$ and $40$ is $600$.