Four speed skaters, marco, naim, oliver, and pedro, compete in a relay race where they all agree that naim will be the last skater. then, they try to decide whether or not oliver should be the first skater in the race. which subset, a, of the sample space shows the complement of the event in which oliver is the first skater in the race?

On traditional maps, earth is represented in a flat plane, or by euclidean geometry. however, a globe is a more accurate model that comes from elliptical geometry. how does a globe represent the fact that there are no parallel lines in elliptical geometry? the equator is not parallel to any other latitudinal lines. the north and south poles are never connected by a geodesic. the geodesics connecting the north and south poles never intersect. the geodesics connecting the north and south poles intersect at both of the poles.