Write each statement in the form "if p . . . then q."

19. Eating 10 hot dogs is sufficient to make someone sick.

20. Two hours in the desert sun is sufficient to give the typical person a sunburn.

21. A valid passport is necessary for travel to France.

Construct a truth table for each compound statement.

18. (~p ~q) (~p q)

19. (~p q) r

20. r (p ~q)

21. (~p ~q) (~r ~p)

22. (~r ~p) (~p ~q)

23. ~ (~p ~q) (~r ~s)

24. (~r s) (~p q)