Two Neighbours

Once there were two ladies who were neighbours. One of them was very fat while the other was very thin. They always kept fighting with each other. All other neighbours were fed up of their quarrels. One day, an elderly person said to both the ladies, "Why do you quarrel so much? Can't you be like the wheels of a two wheeler where one wheel compliments the other?" At this the thin lady said, "Yes, but how can a vehicle move smoothly when one tyre is of a tractor and other of a cycle." Everybody present there started laughing, hearing such a witty answer.