unable to install any update

[Mandar]

mandar@hp-g6:~$ lsb_release -rd
Description: Ubuntu 16.04 LTS
Release: 16.04

mandar@hp-g6:~$ apt-cache policy pkgname
W: Target Sources (main/source/Sources) is configured multiple times in /etc/apt/sources.list.d/numix-ppa-trusty.list:2 and /etc/apt/sources.list.d/numix-ppa-trusty.list:3
N: Unable to locate package pkgname

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: ubuntu-release-upgrader-core 1:16.04.14
ProcVersionSignature: Ubuntu 4.4.0-22.39-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CrashDB: ubuntu
CurrentDesktop: GNOME-Classic:GNOME
Date: Tue May 31 20:22:48 2016
InstallationDate: Installed on 2015-10-23 (221 days ago)
InstallationMedia: It
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: No upgrade log present (probably fresh install)
VarLogDistupgradeTermlog: