When i enter this command sudo apt-get install ros-indigo-desktop-full i got this error

Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 ros-indigo-desktop-full : Depends: ros-indigo-simulators but it is not going to be installed
E: Unable to correct problems, you have held broken packages.
rajiv@rajiv-900x3c-900x3d-900x4c-900x4d:~$ 

Also i already have tried all the commands on this page https://answers.ros.org/question/190177/how-to-install-ros-indigo-in-ubuntu-1404-trusty-64-bit/ without ant success.

Thank you