A small boy who had recently passed his fifth birthday was riding in a suburban car with his mother, when they were asked the customary question, "How old is the boy?" After being told the correct age, which did not require a fare, the conductor passed on to the next person.
The boy sat quite still as if pondering over some question, and then, concluding that full information had not been given, called loudly to the conductor, then at the other end of the car: "And mother's thirty-one!"