sudo apt update && sudo apt upgrade
Hit:1 http://gb.archive.ubuntu.com/ubuntu xenial InRelease
Get:2 http://gb.archive.ubuntu.com/ubuntu xenial-updates InRelease [102 kB]
Get:3 http://gb.archive.ubuntu.com/ubuntu xenial-backports InRelease [102 kB]
Get:4 http://security.ubuntu.com/ubuntu xenial-security InRelease [102 kB]
Get:5 http://gb.archive.ubuntu.com/ubuntu xenial-updates/main amd64 DEP-11 Metadata [305 kB]
Get:6 http://gb.archive.ubuntu.com/ubuntu xenial-updates/main DEP-11 64x64 Icons [194 kB]
Get:7 http://gb.archive.ubuntu.com/ubuntu xenial-updates/universe amd64 DEP-11 Metadata [133 kB]
Get:8 http://gb.archive.ubuntu.com/ubuntu xenial-updates/universe DEP-11 64x64 Icons [162 kB]
Get:9 http://gb.archive.ubuntu.com/ubuntu xenial-updates/multiverse amd64 DEP-11 Metadata [2,520 B]
Get:10 http://gb.archive.ubuntu.com/ubuntu xenial-backports/main amd64 DEP-11 Metadata [3,324 B]
Get:11 http://security.ubuntu.com/ubuntu xenial-security/main amd64 DEP-11 Metadata [68.0 kB]
Get:12 http://security.ubuntu.com/ubuntu xenial-security/main DEP-11 64x64 Icons [48.1 kB]
Get:13 http://security.ubuntu.com/ubuntu xenial-security/universe amd64 DEP-11 Metadata [32.1 kB]
Get:14 http://security.ubuntu.com/ubuntu xenial-security/universe DEP-11 64x64 Icons [37.0 kB]
Fetched 1,292 kB in 2s (534 kB/s)                                   
Reading package lists... Done
Building dependency tree       
Reading state information... Done
All packages are up-to-date.
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run ‘apt-get -f install’ to correct these.
The following packages have unmet dependencies.
 virtualbox-ext-pack : Depends: virtualbox (>= 5.0) but it is not installed or
                                virtualbox-5.0 but it is not installable or
                                virtualbox-5.1 but it is not installable
E: Unmet dependencies. Try using -f.