What symbols and colors stand for on the map?

Physical maps use color most dramatically to show changes in elevation. A palette of greens often displays elevations. Dark green usually represents low-lying land, with lighter shades of green used for higher elevations. In the next higher elevations, physical maps often use a palette of light brown to dark brown.

20: 5

explanation:

about 20% of the world's population lives in   southwest asia, but on less than 5% of the world's   land area.