I am using Ubuntu 18.04 under Windows 10 as a Subsystem, so You have to start off by adding repositories required by MariaDB by :
sudo apt-get install software-properties-common
Then update your installation by :
sudo apt update
Install MariaDB by :
sudo apt install mariadb-server
You’ll be prompted to set a root password and wait for the installation to continue. Issue the following command once installation is complete:
sudo service mysql start
That’s it and to check both your mysql and mariadb version try:
mysql --version