quadrant.rb

class Todo
  attr_accessor :title, :description
  attr_reader :priority, :urgency
  def initialize(priority: 1, urgency: 1)
    @priority, @urgency = priority, urgency
    raise ArgumentError, "urgency must be between 1 and 10" unless (1..10).cover?(@urgency)
    raise ArgumentError, "priority must be between 1 and 10" unless (1..10).cover?(@priority)
  end

  def quadrant
    @quadrant ||= 
      if important? && urgent?
        1
      elsif important? && ! urgent?
        2
      elsif !important? && !urgent?
        3  
      else
        4
      end
    end
  end

  def important?
    (6..10).cover? priority
  end

  def info
    "priority -> #{priority} - urgency -> #{urgency} -  quadrant -> #{quadrant}"
  end

  def urgent?
    (6..10).cover? urgency
  end
end

# Usage Examples
todo = Todo.new(priority: 4, urgency: 3)
puts todo.info
puts "urgent? #{todo.urgent?}"
puts "important? #{todo.important?}"
puts "quadrant #{todo.quadrant}"

Thank you for your feedback. It's really nice. :) Specially the info method and @quadrant = part.