HCF of co-prime numbers $$4$$ and $$15$$ was found as follows by factorisation: $$4=2\times 2$$ and $$15=3\times 5$$ since there is no common prime factor, so HCF of $$4$$ and $$15$$ is $$0$$. Is the answer correct? If not, what is the correct HCF?
No, the answer is not correct.
$$1$$ is the correct HCF.