$ sudo apt-get remove qstat 

Uninstall qstat including dependent package

If you would like to remove qstat and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove qstat 

Use Purging qstat

If you use with purge options to qstat package all the configuration and dependent packages will be removed.

$ sudo apt-get purge qstat 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove qstat 

See Also,