gistfile1.rb

    @problems = MonitorTask.where("date < '#{1.month.ago}'").includes(:problem).collect { |task| task.problem }
    @problems.sort! { |x, y| 
      @count[y.id] ||= @problems.count { |p| p.id == y.id} <=>
      @count[x.id] ||= @problems.count { |p| p.id == x.id}
    }