premise: a motocross bike is jumping through the air between two lines of red tape. hypothesis: The young girl is competing with a few young men in the motocross competition.
neutral: A motocross bike can be ridden by many, not just a young girl.  It can also be ridden for reasons other than competing in a competition.  Also, just because there is on motocross bike does not mean there are also a few young men riding others.