Question

Why there is no LCF or HCM??

Answer 1

It is because Lowest Common Factor and Highest common multiple will always be equal to 1 & infinity respectively.

Answer 2

LCF means lowest common factor which would be 1 for any two numbers.
HCM would be highest common multiple which can't be determined for any two numbers.

So by seeing them we can say that LCF and HCM will be of no use in any situation.