error of uninstall gem

gem uninstall rake

Select gem to uninstall:
1. rake-0.8.7
2. rake-0.9.2
3. All versions


ERROR: While executing gem ... (Gem::FilePermissionError)
    You don't have write permissions into the /usr/local/lib/ruby/gems/
1.9.1 directory.

Is there a question here? Is that error message somehow ambiguous?

are you try "sudo gem uninstall rake" ?

thanks, i can uninstall it..