I searched on Google but everything I could find was about AMD removing the support for Ubuntu 16.04. Lots of people mentioned there is an open-source driver but I couldn't find it and I am not sure I can set it up even if I find it. So, it would be great if someone tells me how I can install the drivers for AMD Radeon HD7850 for Ubuntu 16.04.
This is question is answered here. How to install Radeon Open Source Driver?
Purge AMD catalyst
sudo apt-get purge fglrx
xserver-xorg-video-ati make sure you have the ATI driver first
xf86-video-ati (or let dpkg resolve it.)