Question

Find the smallest number exactly divisible by $12,21$ and $18$ .

Answer 1

Given , the numbers are $12,21$ and $18$

For finding the smallest number finding LCM of the given number .

So , Prime factors of the given number are

$12=2\times 2\times 3$

$21=3\times 7$

$18=2\times 3\times 3$

LCM of the numbers are $=2\times 2\times 3\times 3\times 7$

LCM of the numbers are $=252$

Hence, the required smallest number is $252$ .