Saiprem, Ubuntu installs everything from apt-get and through a .deb in /usr/bin/ (if that's what you're referring to) and anything compiled from source is typically placed in /usr/local/bin/.
The reason you can not find it immediately afterward is because you need to reindex the system. Ubuntu does this automatically, although when I last used Ubuntu it was very buggy and I always had to disable the thing, but it only does it once a day.
To update it manually, run:
And that will repopulate the locate database. Then locate what you're looking using the 'locate' command. 'Find' will also work, but, as it searches manually through all the directories, this is much slower. It's simpler just to update the index to have it ready to go.
Also, sometimes command names aren't exactly the same as what you'd think. It could be capitalized (running commands is case-sensitive), it could be 'moneyd' or 'mdance' or even just 'md'. This should be located in the README in the tar.