Installing R on Ubuntu 64x

edit /etc/apt/sources.list
paste deb https://cloud.r-project.org/bin/linux/ubuntu trusty-cran35/
sudo apt-get update
sudo apt-get install r-base (first uninstall if already older version R base is installed using sudo apt-get remove r-base)
sudo apt-get install r-base-dev
sudo apt-get install r-base-dev
Y or I : install the package maintainer's version