Installing CUDA 7.0 on Ubuntu 14.04

I am trying to install the CUDA toolkit 7.0 (https://developer.nvidia.com/cuda-toolkit) on Ubuntu 14.04 without luck. I have been following a guide ( http://www.r-tutor.com/gpu-computing/cuda-installation/cuda7.0-ubuntu) stating that the when the .deb file is downloaded three simple commands should do the trick:

sudo dpkg -i cuda-repo-ubuntu1404-7-0-local_7.0-28_amd64.deb
sudo apt-get update
sudo apt-get install cuda

However when I am executing the last command I get the following:

Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package cuda

What am I missing here?

You will have to add the file to your software list.

After running

sudo dpkg -i cuda-repo-ubuntu1404-7-0-local_7.0-28_amd64.deb

open Softwares & Updates (search for it in the Dash)

In the Other Software tab, enable the checkbox corresponding to your package. It will be of the form

file:///var/cuda...

Then run the following:

sudo apt-get update
sudo apt-get install cuda

If it complains about any dependencies, add those also to the above command.

For example, I got cuda-7-5 and cuda-runtime-7-5 as unmet dependencies. So my final install command was

sudo apt-get install cuda cuda-7-5 cuda-runtime-7-5