Let us take an example

If you want to find the Lcm of 5,12,15

Step1:first take the largest digit I,e 15

Step2 :you have to take multiples of 15

For example:15,30,45,60,75,90...............

Step 3:take that multiple of 15 which is also multiple of other two digits

For example 60 is multiple of 15 but also multiple of 5 and 12

60 will be ur answer

Thank you