Can't install a package due to "Something wicked happened resolving" error [duplicate]

I'm following these instructions to install git on my laptop.
When I do:

$ sudo apt-get install git-core

This is what my terinal shows:

Reading package lists... Done
Building dependency tree        
Reading state information... Done
The following packages were automatically installed and are no longer required:   
  libasprintf0c2:i386
  libcroco3:i386
  libgettextpo0:i386
  libgomp1:i386
  libunistring0:i386
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  git git-man liberror-perl
Suggested packages:
  git-daemon-run
  git-daemon-sysvinit
  git-doc git-el
  git-arch git-cvs
  git-svn
  git-email
  git-gui
  gitk gitweb
The following NEW packages will be installed:
  git git-core git-man liberror-perl

 0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
 Need to get 6,825 kB of archives. After this operation, 15.3 MB of additional disk space will be used. Do you want to continue [Y/n]? y
 WARNING: The following packages cannot be authenticated!
   liberror-perl git-man git git-core
Install these packages without verification [y/N]?

  E: Some packages could not be authenticated
lucas@lucas-Inspiron-N5050:~$ sudo apt-get install git-core
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer required:
  libasprintf0c2:i386
  libcroco3:i386
  libgettextpo0:i386
  libgomp1:i386
  libunistring0:i386
Use 'apt-get autoremove' to remove them.
The following extra packages will be installed:
  git git-man liberror-perl
Suggested packages:
  git-daemon-run git-daemon-sysvinit
  git-doc git-el git-arch git-cvs git-svn
  git-email git-gui gitk gitweb
The following NEW packages will be installed:
  git git-core
  git-man liberror-perl
 0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
 Need to get 6,825 kB of archives. After this operation, 15.3 MB of additional disk space will be used. Do you want to continue [Y/n]? y
WARNING: The following packages cannot be authenticated!
  liberror-perl git-man git git-core
Install these packages without verification [y/N]? y
Err httpq://py.archive.ubuntu.com/ubuntu/quantal/main liberror-perl all 0.17-1
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git-man all 1:1.7.10.4-1ubuntu1
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git amd64 1:1.7.10.4-1ubuntu1
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
Err httpq://py.archive.ubuntu.com/ubuntu/ quantal/main git-core all 1:1.7.10.4-1ubuntu1
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
 Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/libe/liberror-perl/liberrorperl_0.17-1_all.deb
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
 Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/g/gi/git-man_1.7.10.4-1ubuntu1_all.deb
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
 Failed to fetch httpq://py.archive.ubuntu.com/ubuntu/pool/main/g/git/git_1.7.10.4-1ubuntu1_amd64.deb
   Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
 Failed to fetch http://py.archive.ubuntu.com/ubuntu/pool/main/g/git/git-core_1.7.10.4-1ubuntu1_all.deb
  Something wicked happened resolving 'py.archive.ubuntu.com:http' (-5 - No address associated with hostname)
E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

How could I install git on Ubuntu 12.10? I can't even do it from the Ubuntu Software Center.

Thanks in advance!

Close all programs/windows which have to do with installing software e.g. Synaptic, software-centre and terminals.

Now you should delete the locked files:

You can delete the lock file with

sudo rm /var/lib/apt/lists/lock

you may also need to delete the lock file in the cache directory

sudo rm /var/cache/apt/archives/lock 

by: this answer

and now you should open a terminal and run:

 sudo apt-get update --fix-missing

and now you can install everything you want again.
Have a nice day

Do you have a static IP which you set in /etc/networks/interfaces? I had a similar problem after I upgraded to Ubuntu 12.04. The problem was that the DNS server was no longer set in /etc/resolv.conf and regardless what you put there it was overwritten at reboot. The solution is to add in /etc/networks/interfaces this:

dns-nameservers `<IP address of the DNS server>`
dns-domain `<the name of the domain>`

As a quick fix is to add the nameserver in resolv.conf, but it will disappear after you reboot.