link_to('link text', url, :remote => true) does which of the following?

If a method is protected:

All Ruby number objects are instances of class _____.

Which is valid objects of class Integer or one of its subclasses? 1) -123 2) 0xFF 3) 123_456_789 4) 123456789123456789123456789123456789

What's an equivalent way of performing the following (h is a Hash): h.each { |k,v| h.delete k if k.nil? }

In The Author Model, how do you create a nested association between Authors and Blogs?

Which of these options is right to create default scope of model in Rails?

Which of these files determine Ruby version and gemset for RVM library?

Which statement is true regarding the find_or_create method in Ruby on Rails?

Which of the following protects 'NOT NULL' fields against missing a user input?

Which is not an advantage of using an integrated development environment (IDE) for Rails ,compared with using a simple text editor?