Upgrade subject to access all content

What is the period of a simple pendulum with a length of $3L$ and a mass of $2M$?

$2\pi \sqrt { \cfrac { L }{ g } } $

$2\pi \sqrt { \cfrac {3 L }{ g } } $

$2\pi \sqrt { \cfrac {6M L }{ g } } $

$2\pi \sqrt { \cfrac { 3L }{ 2Mg } } $