Question

Find the HCF of $144,252,630$ by prime factorisation method .

Answer 1

First find the prime factors of each number then check common factors.

Prime factorization of $144=2\times 2\times 2\times 2\times 3\times 3$

Prime factorization of $252=2\times 2\times 3\times 3\times 7$

Prime factorization of $630=2\times 3\times 3\times 5\times 7$

Here common factors are $2\times 3\times 3$

So, H.C.F $\{144,252,630\}=18$