Question

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?

Answer 1

Find the HCF of co-prime numbers $4$ and $15$

Given: Co-prime numbers $4$ and $15$

HCF is the greatest number which divides each of the two or more numbers. It can be calculated by a common prime factor.

By Factorisation,

$$\begin{gathered} 4=1\times 2\times 2 \\ 15=1\times 3\times 5 \end{gathered}$$

The common factor of the given co-prime numbers $4$ and $15$ is $1$. So HCF is $1$.

Hence, the answer is not correct and the correct HCF is $1$.