To convert .djvu files to .pdf in linux mint or ubuntu is so very easy.
Install djvulibre-bin and djview by the following commands
sudo apt-get install djuvlibre-bin
sudo apt-get install djview
Now open your djvu file using djview and go to File --> Export as. Select pdf and you're done!
Install djvulibre-bin and djview by the following commands
sudo apt-get install djuvlibre-bin
sudo apt-get install djview
Now open your djvu file using djview and go to File --> Export as. Select pdf and you're done!