install rails 3 fedora 13 issues

i am in trouble i am new on fedora want to install rails 3 only how
can i please help me
if any one did that then please send me the tutorial link
issue i am facing is ruby version 1.8.6 is installed here and on using
rvm its does not change suggest me please
rvm use 1.8.7 show using ruby 1.8.7
then ruby -v shows its 1.8.6
please help

Thanks in advance

i am running this fedora13 on windows like virtual machine

and also new bie on fedora

You just need to restart terminal and than first make sure you can run
rvm list or any rvm command. and than use this command <code> rvm --
default ruby-1.8.7 </code>