docs http://api.rubyonrails.org/classes/Array.html#method-c-wrap in_groups_of api.rubyonrails.org/classes/Array.html#method-i-sample Array.wrap Array http://api.rubyonrails.org/classes/Array.html#method-i-in... http://api.rubyonrails.org/classes/Array.html#method-i-fo...