amusement on a particularly boring transatlanfic fight one of the authors am used himseft by counting the heads of the people in the seats in front of him. He noticed that all 37 of them either had black hair or had a whole row to themselves or both. Of this total 33 had black hair and 6 were fortunate enough to have a whole row of seats to themselves. How many black haired people had whole rows to themselves?