**Question:**

If* a* and *b* are relatively prime, what is their LCM?

**Solution:**

If two numbers are relatively prime then their greatest common factor will be 1.

∴ HCF(*a*, *b*) = 1

Using the formula, Product of two numbers = HCF × LCM

we conclude that,*a* × *b* = 1 × LCM

∴ LCM = *ab*

Thus, LCM(*a*, *b*) is *ab*.