dependencies not installed for python3.6 when installing 3.6-dev

[Dhruv Singal]

Description: Ubuntu 18.04.1 LTS
Release: 18.04
Minimal Install

sudo apt-get install python3-dev python-dev python3-pip python-pip
Reading package lists... Done
Building dependency tree
Reading state information... Done
python-dev is already the newest version (2.7.15~rc1-1).
python-pip is already the newest version (9.0.1-2.3~ubuntu1).
python3-pip is already the newest version (9.0.1-2.3~ubuntu1).
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 python3-dev : Depends: libpython3-dev (= 3.6.5-3ubuntu1) but it is not going to be installed
               Depends: python3.6-dev (>= 3.6.5-2~) but it is not going to be installed
E: Unable to correct problems, you have held broken packages.

Expected: package to be installed.