Question

I am the smallest number which is 3 more than a number which is completely divisible by 15 and 20. Identify me.

Answer 1

The smallest number, which is completely divisible by $15$ and $20$ is the LCM of both the numbers.

So, by prime factorisation we get,
$15=3\times 5$
$20=2\times 2\times 5$

$\therefore$ LCM of $15$ and $20$ is $2\times 2\times 3\times 5=60$

The required number is $3$ more than $60$ i.e $63$.