So, you are in a situation where you have no idea what version of Ubuntu is installed (perhaps the display has been radically altered), so long as you can get terminal access, finding out is very simple. Open a terminal, this can most always be done with CTL+ALT+T, unless someone changed that too. In your terminal issue the command "lsb_release -a", as shown here:
As you can see, the output contains the version!
“Live as if you were to die tomorrow. Learn as if you were to live forever.”