Over a period of time, when packages are installed using apt-get commands in Linux Mint/Ubuntu, the corresponding .deb files are stored in the archives folder (/var/cache/apt/archives). They can take up disk space if left as it is and so it can be useful to remove them.
These files can be viewed by typing :
ls -l /var/cache/apt/archives | less
To remove them and empty the archives folder :
1. Open Terminal and type :
sudo apt-get clean
All done. The earlier .deb files will now no longer be there.
Happy cleaning.