I installed nodejs on ubuntu from instructions given here
When I write node --version in the terminal I see this : -bash: /usr/sbin/node: No
node --version
-bash: /usr/sbin/node: No
Just use NVM(Node Version Manager) - https://github.com/creationix/nvm
It has become the standard for managing Node.js.
When you need a new version:
nvm install NEW_VER nvm use XXX
If something goes wrong you can always go back with
nvm use OLD_VER