Question

Find the HCF of the following numbers using prime factorisation method.

$72,108,180$

Answer 1

To find the HCF of given numbers, First we find their common factors by prime factorisation. Then multiplication of the common factors would be the HCF of given numbers.

For the HCF of $72,108,180$

$72=2\times 2\times 2\times 3\times 3$

$108=2\times 2\times 3\times 3\times 3$

$180=2\times 2\times 3\times 3\times 5$

Common factors of $72,108,180$ is $2,2,3,3$

HCF of $72,108,180$ is $2\times 2\times 3\times 3=36$

Hence, HCF of the given numbers is $36$.