5. In how many states may a man legally marry his widow's sister? Answer:

This question is a reference to a legal case, Reynolds v. United States, 98 U.S. 145 (1898), in which the U.S. Supreme Court ruled that a law prohibiting polygamy did not violate the First Amendment's protection of religious beliefs. The question is a play on words and is not meant to be taken literally. The answer is 0, as it is not legal for a man to marry his widow's sister.