Premise: a skateboarder grinds a rail .
Correct statement: There is a better than even chance that a skateboarder is wearing a helmet .
Incorrect statement: There is little chance that a skateboarder is wearing a helmet .
Correct statement: It is likely that a skateboarder is performing .
Incorrect statement: It is highly unlikely that a skateboarder is performing .
Correct statement: It is impossible that an expert skateboarder rides a rail .
Incorrect statement: It is likely that an expert skateboarder rides a rail .
Correct statement: It is impossible that a skateboarder doing tricks in a pool .
Incorrect statement: There is a better than even chance that a skateboarder doing tricks in a pool .
Correct statement: There is almost no chance that a skateboarder is at a competition .
Incorrect statement: There is a better than even chance that a skateboarder is at a competition .