Ruby class set/get

What is wrong with this set/get?

class Pupil
  def name
    @name
  end

  def name=(name)
    @name = name
  end

  def age
    @age
  end

  def age=(age)
    @age
  end
end

Further on the same, if there was a child class with 3 arguments, name, age, sex, would the set get method in the child for sex only. Can you please show the set/get method and initialize in the child class.