Question

Find the HCF of the numbers $70,105$and $75$

Answer 1

Highest common factor is the greatest common divisor that can divide all of these numbers leaving $0$ as a remainder.

HCF of the numbers $70,105,$and $75$, by prime factorisation

$$\begin{gathered} 70=2\times 5\times 7 \\ 105=3\times 5\times 7 \\ 75=3\times 5\times 5 \end{gathered}$$

The prime factors that are common in all the three numbers is $5$ and $7$.

So, the HCF will be $35$.