Question

Find the $HCF$ of the following
$18,54,81$

Answer 1

Write the numbers as product of their prime factors,

$18=2\times 3\times 3$

$54=2\times 3\times 3\times 3$

$81=3\times 3\times 3\times 3$

Hence,

$HCF(18,54,81)=3\times 3$

$=9$