If this command does not solve your problem
sudo dpkg --configure -a
Remove troubled packages from the file /var/lib/dpkg/status
1) First make back up of status file.
2) Search these three packages
and remove the whole paragraph of these packages, it will be appeared in the file like this
Status: install ok installed
Maintainer: Ubuntu Developers <firstname.lastname@example.org>
Provides: apache2, apache2-mpm, httpd, httpd-cgi
Depends: apache2.2-common (= 2.2.22-6ubuntu2.3), apache2.2-bin (= 2.2.22-6ubuntu2.3)
Conflicts: apache2-common, apache2-mpm
Description: Apache HTTP Server - traditional non-threaded model
Each Apache Multi-Processing Module provides a different "flavor" of
web server binary, compiled with a different processing model.
The prefork MPM provides a non-threaded implementation using a variable
number of processes where each process handles only one connection
at the same time. It is not as fast as threaded models, but is considered to
be more stable. It is appropriate for sites that need to maintain
compatibility with non-thread-safe libraries, and is the best MPM for
isolating each request, so that a problem with a single request will not
affect any other.
Original-Maintainer: Debian Apache Maintainers <email@example.com>
Now try to install it again.