$ sudo apt-cache policy <package name>

Example:

$ sudo apt-cache policy drush
drush:
  Installed: 5.8-1
  Candidate: 5.8-1
  Version table:
 *** 5.8-1 0
        500 http://dk.archive.ubuntu.com/ubuntu/ raring/universe amd64 Packages
        100 /var/lib/dpkg/status