Three builder friends Elly, Glen, and Mistri work in the same construction company. Glen can build a wall in the same time as Elly and Mistri will build working together. If Glen and Mistri can make the wall in 8 days while Elly makes it in 40 days alone then how much time will it take Mistri to make the same wall on his own?

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.