Question

The least perfect square number which is divisible by each of $21,36,$ and $66$ is

• A. $213444$
• B. $214344$
• C. $214434$
• D. $231444$

Answer 1

The correct option is A $213444$

$21=3\times 7$
$36=2\times 2\times 3\times 3$
$66=2\times 3\times 11$
So LCM of 21,36,66$=2\times 2\times 3\times 3\times 7\times 11=2772$
To make a perfect square ,it must be multiplied by$7\times 11$
So Required number$2^2\times 3^2\times 7^2\times {11}^2=213444$