Premise: A bearded man in a white t-shirt is riding a motorcycle .
Correct statement: It is impossible that some riders belonging to a rider club are competing in a motorcycle race
Incorrect statement: It is certain that some riders belonging to a rider club are competing in a motorcycle race
Correct statement: Chances are about even that the man is going fast
Incorrect statement: It is certain that the man is going fast
Correct statement: It is highly unlikely that a man is riding a motorcycle on a dirt road .
Incorrect statement: There is a better than even chance that a man is riding a motorcycle on a dirt road .
Correct statement: Chances are about even that a hairy biker , dressed in white , rides away .
Incorrect statement: It is certain that a hairy biker , dressed in white , rides away .
Correct statement: There is a very good chance that the motorcycle is being driven by a large man with a beard .
Incorrect statement: Chances are slight that the motorcycle is being driven by a large man with a beard .