If you are given the coordinates 20° north, 30° west, they will be whether you are looking on a globe or a mercator projection or using a gps device in the real world.

If you are given the coordinates 20 degrees north, 30 degrees west, they will be the same, no matter weather you are looking on a globe or a Mercator projection or using a GPS device in the real world.
All of them will show the same place because the latitude is pretty close to the Equator, so the deformations are still not taking part in here, unlike at bigger latitudes. They will all show the same spot in the North Atlantic Ocean.

Ibelieve the answer is c. map projections.hope my answer has you : )

F=31 because you subtract 39-8