The Will Will Rule!
A man dying left his wife in expectation, that a child would be afterward added to the surviving family; and making his will ordered that, if the child were a son, 2/3 of his estate should belong to him, and the remainder to his mother; but if it were a daughter, he appointed the mother 2/3, and the child the remainder. But it happened, that the addition were both a son and a daughter, by which the widow lost in equity 2400 pounds more than if there had been only a girl. what would have been her dowry, had she had only a son?
The book gave an answer of 2100 pounds.
Source: Samuel Webber's Mathematics Compiled from the Best Authors, 1808, p. 212.