Steps To Install LAMP In UBUNTU

First of all open, Applications>>Accessories>>Terminal , then in Terminal type the following command:
                            sudo apt-get install lamp-server^
Give the administrative password and hit Enter, it will show the following screen,
Enter the password for MYSQL root user , press tab and hit Enter.It will install apache2 as well as php.

Now repeat the password for MYSQL

To install phpmyadmin, type the following command:

 sudo apt-get install libapache2-mod-auth-mysql phpmyadmin

It will show the following screen,select apache2 by pressing spacebar key, then press tab and hit enter,it will then install phpmyadmin

After that the next screen will come up, choose 'yes' and hit Enter

  Now give the password for database's administrative user,

It will next ask for the password for phpmyadmin

Now repeat the password for phpmyadmin

phpmyadmin is now installed.
Testing
To test the working of apache, go to your web browser and type 'http://localhost/' in the address bar, then it will show the following screen which means your apache is working.

To test the working of php, type in terminal:
                      sudo gedit /var/www/testing.php
It will create testing.php file in your /var/www/ folder and in that file , write 
  <?php
  phpinfo();
  ?>
and then save the file.After that type the following command in Terminal,
                          sudo /etc/init.d/apache2 restart
Now go to your browser and type 'http://localhost/testing.php' , it will show the following screen

To check phpmyadmin working, type 'http://localhost/phpmyadmin/' in your browser,it will show the following screen

Now login with username 'root' and enter the password you created earlier,and you will get this screen,

Your LAMP is completely installed now.