How to Add Ruby Ubuntu PPA Repository
This short guide shows you Step-by-step How to Add Ruby Ubuntu Repository PPA.
And this Repository includes Several Ruby Versions, from Ruby 2.0 Up to the Latest Ruby Release.

Open Terminal Window
(Press “Enter” to Execute Commands)
Or Login into Server Shell Shell…Enabling Ruby Ubuntu PPA
sudo add-apt-repository ppa:brightbox/ruby-ng
Then Reload the Apt Sources with:
sudo apt update
How to Getting-Started with Ruby on Ubuntu Linux