Error downloading package

If you hit Ctrl-C while apt-get is running, you may see this message if you run it again:

E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

Solution:

$ sudo rm -rf /var/lib/dpkg/lock
$ sudo rm -rf /var/cache/apt/archives/lock 
$ sudo rm -rf /var/lib/apt/lists/lock