Premise: A surfboarder emerging from the ocean with his board , as the waves crash ashore behind him .
Correct statement: It is impossible that the surfer became afraid when he saw the wave behind him .
Incorrect statement: It is certain that the surfer became afraid when he saw the wave behind him .
Correct statement: Chances are slight that the surfer 's board has sticky wax on it .
Incorrect statement: It is likely that the surfer 's board has sticky wax on it .
Correct statement: Chances are about even that the waves are really big .
Incorrect statement: It is almost certain that the waves are really big .
Correct statement: We doubt that a man is carrying his surfboard above his head .
Incorrect statement: It is certain that a man is carrying his surfboard above his head .
Correct statement: There is a very good chance that a surfer is wearing swim trunks .
Incorrect statement: It is impossible that a surfer is wearing swim trunks .